Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/asia.202200239

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/asia.202200239

Language：English   Publishing type：Research paper (bulletin of university, research institution)   Publisher：Institute of Science and Engineering  

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)   Publisher：中央大学理工学研究所  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society  

DOI： 10.1021/acs.joc.1c01440

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Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acs.orglett.1c01294

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/ajoc.202100184

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/ajoc.202100184

Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society  

DOI： 10.1021/acs.orglett.9b00875

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Chemical Society  

DOI： 10.1039/D0DT03213A

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry  

DOI： 10.1039/D0CC04013D

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Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acs.joc.0c01023

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)   Publisher：中央大学  

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/ejoc.201900738

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACS  

DOI： 10.1021/acs.joc.8b02309

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Chemical Society of Japan  

DOI： 10.1246/bcsj.20170415

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：RSC  

DOI： 10.1039/c8ra05293j

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Twisted polycyclic aromatic hydrocarbons (PAHs) were prepared by the successive rhodium-catalyzed annulation and dehydrogenative cyclization of bis(arylethynyl) arenes with di-tert-butylbiphenyl-2-ylboronic acid. The molecular structures of the PAHs were determined by single-crystal XRD analysis. The PAHs showed up to four fjord regions, and the twisting angle was 46.78. The nonplanarity (NP) and harmonic oscillator model of aromaticity (HOMA) were calculated by using the structural data obtained from XRD analysis. The PAHs derived from dialkynyl naphthalenes showed low planarity and HOMA of the central ring. The optical properties of the PAHs were investigated by UV/Vis absorption and fluorescence spectroscopy analyses. The absorption and emission maxima of the PAHs with a larger planar region appeared at a longer wavelength. DFT calculations support that the absorption band at lambda approximate to 450 nm can be mainly attributed to the HOMO-LUMO transition.

DOI： 10.1002/chem.201602474

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

AgOAc/ThioClickFerrophos (TCF) complex catalyzed the 1,3-dipolar cycloaddition of azomethine ylides (glycine imino ester) to nitroalkenes. The corresponding endo-cycloadducts (88:12-98:2 endo/exo) were afforded in good yields with high enantioselectivities, up to 98% ee, without addition of external amine. AgOAc/TCF works as a bifunctional (Lewis acid and base) catalyst. (C) 2015 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2015.08.002

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

N-Hetero-ortho-phenylene hexamers with two 2,3-substituted pyridine moieties (i.e., 1a-c) were prepared by palladium-catalyzed homocoupling with pyridine-directed C-H cleavage as the key step. The conformations of the resulting hexamers in solution and in the solid state were investigated by computational methods, X-ray analysis, and H-1 NMR spectroscopy. Calculations at the SCS-MP2/def2-TZVPP//B97-D3(bj)/def2-SVP level suggested that helical folding of 1a as the pyridine moieties are stacked is thermally more stable than the equivalent folding in the unsubstituted ortho-phenylene hexamer. The conformations of single crystals of 1 were consistent with the optimized structures obtained by DFT calculations. Except for rotation of the terminal phenyl groups, only one set of signals corresponding to a helical conformation was observed by analysis of 1 by H-1 NMR spectroscopy in CDCl3 solution.

DOI： 10.1002/ejoc.201501270

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY  

DOI： 10.1002/ejoc.201501270

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/chem.201502746

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Silver/ThioClickFerrophos (Ag(I)/TCF) catalyzed the asymmetric Michael addition of an azomethine ylide to arylidene diphosphonates to give syn adducts as the major diastereomers in good yields with high enantiomeric excesses. (C) 2015 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2015.03.024

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：SOC SYNTHETIC ORGANIC CHEM JPN  

The studies on nickel (0) -catalyzed three-component reactions via C-H and C-C bond activation were described. Highly regio- and stereoselective cross-trimerization of alkynes proceeded to give the corresponding 1,3-diene-5-yne by combination of triisopropylsilylacetylene and identical or distinct two alkynes via selective terminal C-H bond activation of triisopropylsilylacetylene in the presence of Ni(cod)(2)/phosphine catalyst. The methodology could be also extended toward the three-component reaction among two alkynes and a norbornene to give the 1,5-enyne. On the other hand, our interest also focused on three-component reductive coupling reaction between ring-strained cyclic alkene, aryl aldehyde and silane. Using methylenecyclopropane, reductive coupling reaction with aryl aldehyde and triisopropylsilane proceeded to yield silylated allylic alcohols via C-C bond cleavage of methylenecyclopropane ring in the presence of Ni(cod)(2)/NHC catalyst. We also found an unprecedented three-component reductive coupling via aromatic C-H bond activation of aryl aldehyde at the ortho position by combination with norbornene and triisopropylsilane leading to silylated indanol using Ni(cod)(2)NHC catalyst.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

DOI： 10.1002/anie.201101468

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

The palladium complex bearing a novel NHC-ligand derived from 1,4-dimesityl-1,2,3-tirazole was prepared. The complex catalyzed the Suzuki-Miyaura coupling reaction with aryl chloride successfully to give biaryls in excellent yields, particularly very effective for the sterically hindered reaction between o-substituted arylchlorides and o-substituted phenylboronic acids.

DOI： 10.1246/cl.2010.920

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

A series of P,S ligands (ThioChckFerrophos) based on a triazoleferrocenylethyl backbone were synthesized in a four-step sequence by click chemistry methodology. The new P,S ligands were applied in allylic alkylations, etherifications, and animations of 1,3-diphenylprop-2-enyl acetate catalyzed by Pd complexes. These reactions proceeded smoothly to give products in good yields and with good enantioselectivities of up to 90 % ee. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

DOI： 10.1002/ejoc.200900766

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

A series of diphosphine ClickFerrophos ligands (CF), based on a triazoleferrocene backbone, was synthesized in a four-step sequence via click chemistry methodology. In addition to the four previously synthesized ligands CF1, CF4, CF7 and CF10, six novel CF ligands CF2-3 and CF5-8 were prepared. Hydiogenation reactions of alkenes and ketones were significantly improved upon by using CF ligands as rhodium- or ruthenium-complexes in which the % ee values can be optimized by choosing the appropriate CF ligand depending on the substrate. (C) 2009 Elsevier Ltd All rights reserved

DOI： 10.1016/j.tetasy.2009.09.004

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DOI： 10.1016/j.tetlet.2009.02.214

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：GEORG THIEME VERLAG KG  

We have prepared several ClickFerrophos families and tested for the Cu(I)-catalyzed asymmetric reductive aldol reaction of ketones and aldehydes with an acrylic ester in the presence of phenylsilane. The Cu(I)-ClickFerrophos complex is efficient for the reaction of ketones with methyl acrylate to afford the erythro adducts both highly diastereo- and enantioselectively; the diastereomeric ratio of erythro/threo is improved when compared to the analogous Taniaphos.

DOI： 10.1055/s-0029-1216724

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society  

The first highly selective 1:2 cross-trimerization between triisopropylsilylacetylene and 2 equiv of internal alkynes, leading to 1,3-diene-5-yne compounds, was achieved using the Ni(cod)2/PnPr3 catalyst. Various symmetrical and asymmetrical internal alkynes could be used for the cross-trimerization reaction with high regio- and stereoselectivity.

DOI： 10.1021/ja900146u

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DOI： 10.3987/COM-08-11546

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

The pinacol coupling reaction of (Rp)-2-diphenylphosphanyl ferrocenecarbaldehyde (1) was smoothly mediated by divalent samarium triflate to give (R,R)-diol 2a predominantly, whereas the use of samarium(II) iodide resulted in low selectivity as described in the previous literature. In contrast, the coupling reaction of (Rp)-2-diphenylphosphoryl ferrocenecarbaldehyde (3) with Sm(OTf)(2) gave the (S,S)-diol as the major isomer, which was the opposite stereochemistry of that obtained in the reaction with 1. The rhodium complexes of diphosphanes 2a were good catalysts for the asymmetric hydrogenation of alpha-acetamidocinnamic acid, and the product was obtained quantitatively with up to 92% ee. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

DOI： 10.1002/ejoc.200801138

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

DOI： 10.1002/anie.200902099

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Georg Thieme Verlag  

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

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Language：English   Publisher：Eur.J.Org.Chem  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE SA LAUSANNE  

Twenty new ferrocenyl organyl (alkyl, alkenyl and alkynyl) tellurides were synthesized by using diferrocenyl ditelluride and characterized spectroscopically. Cinnamyl and benzyl ferrocenyl tellurides were revealed to be air stable enough to be isolated, in sharp contrast to the corresponding air sensitive phenyl tellurides. Treatment of some alkyl ferrocenyl tellurides with 1 mol equiv of m-chloroperbenzoic acid (MCPBA) in diethyl ether at 25-degrees-C for 2 h in the presence of triethylamine or tetracyanoethylene (TCNE) afforded the corresponding alkenes in fair to good yields via telluroxide elimination. The MCPBA or air oxidation of some allylic ferrocenyl tellurides in ethanol produced the corresponding allylic alcohols via [2,3] sigmatropic rearrangement. H-1 NMR and electronic absorption spectroscopic studies revealed that donor-acceptor complexes between alkyl ferrocenyl tellurides and TCNE were produced, an improvement of telluroxide elimination in the presence of TCNE being attributed to this complex formation.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：VCH pullishevs  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：英国化学会  

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Language：English   Publishing type：Research paper (scientific journal)  

Samarium(II) di-iodide, which is a strong one-electron transfer reducing agent, is effective for the reductive coupling of α,β-unsaturated esters with carbonyl compounds, whereby substituted γ-lactones can easily be prepared in good to excellent yields under very mild conditions. Two mole equiv. of samarium(II) di-iodide to each mole equiv. of starting substrate always give reasonable yields. The presence of an alcohol is essential in the reaction, complex unidentified products being formed in the absence of an alcohol
t-butyl alcohol gave more satisfactory results than methanol and ethanol. The alcohol acts as a proton donor, the use of MeOD leading to a deuteriated γ-lactone. The reaction is applicable to both aliphatic and aromatic ketones or aldehydes, whereas the electrochemical method is limited to aliphatic substrates. The diastereoselectivity is examined in the reaction of 4-t-butylcyclo-hexanone with ethyl acrylate
an anti-isomer is produced predominantly (syn: anti = 1:9) as the result of selective axial attack. The reaction may proceed by a radical mechanism, and reaction may not involve a samarium ester homoenolate. The reaction is extended to the intramolecular reaction of an α,β-unsaturated keto ester (8-oxonon-2-enoate) leading to the ready synthesis of a bicyclic γ-lactone. © 1988, The Royal Society of Chemistry. All rights reserved.

DOI： 10.1039/P19880001669

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

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Responsible for pages：1192-1193   Language：English   Book type：Scholarly book

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Language：English   Publisher：AMER CHEMICAL SOC  

A AgOAc/ThioClickFerrophos complex-catalyzed the highly diastereo- and enantioselective reaction between 1-pyrroline-5-carboxylates (1) and acyclic alpha-enones (2) in MeOH, in the presence of DBU, to give the single isomer Michael adducts (3) in high yields (up to 99%) with excellent enantioselectivies (up to 99% ee). Subsequent reduction of the Michael adducts with sodium cyanoborohydride successfully produced the fused pyrrolizidine ester as an almost pure single stereoisomer.

DOI： 10.1021/acs.joc.7b01335

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Language：English   Publisher：American Chemical Society  

The first example of palladium-catalyzed direct formylation of arylzinc reagents using S-phenyl thioformate is reported. The reaction proceeded under mild conditions, allowing high functional group tolerance. In addition, the developed formylation method was used to prepare deuterated and 13C-labeled aryl aldehydes from isotope-labeled S-phenyl thioformates. Moreover, this procedure was applied to an alkenylzinc halide, affording the corresponding enal.

DOI： 10.1021/acs.orglett.7b00447

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Language：English   Publisher：American Chemical Society  

The first example of palladium-catalyzed direct formylation of arylzinc reagents using S-phenyl thioformate is reported. The reaction proceeded under mild conditions, allowing high functional group tolerance. In addition, the developed formylation method was used to prepare deuterated and 13C-labeled aryl aldehydes from isotope-labeled S-phenyl thioformates. Moreover, this procedure was applied to an alkenylzinc halide, affording the corresponding enal.

DOI： 10.1021/acs.orglett.7b00447

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Language：English   Publisher：WILEY-V C H VERLAG GMBH  

Derivatives of the ortho-phenylene hexamer containing pyridine moieties and hydroxy groups were prepared through Negishi cross-coupling reactions between bis(chloropyridyl)biphenyl and alkoxy-substituted arylzinc reagents. X-ray diffraction analysis revealed a closed helical folding directed by pi-pi stacking and hydrogen bonds. No broadening or coalescence of H-1 NMR peaks was observed between 213 and 313 K, which indicates the high stability of the helical folding in CDCl3 solution. DFT calculations on the rotation of a single bond in the obtained compound indicated that the intramolecular hydrogen bonds led to exceptional stabilization of the closed helical folding. Right and left helices were separated by chiral column chromatography.

DOI： 10.1002/ejoc.201700102

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Language：English   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

The silver/ThioClickFerrophos (a chiral ferrocenyl P,S-ligand)-catalyzed Michael additions of 2-oxazolineand thiazoline-4-carboxylate to nitroalkenes were highly anti-selective and enantioselective and produced the corresponding adducts in high yields. (C) 2017 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetasy.2017.02.001

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Language：English   Publisher：AMER CHEMICAL SOC  

The copper-catalyzed asymmetric conjugate addition of 2-oxazoline- and 2-thiazoline-4-carboxylate to a nitroalkene proceeded to give either the syn or anti adduct selectively in high enantiomeric excess when an appropriate chiral ligand was used. Subsequent reduction of the nitro group followed by hydrolysis of the oxazoline ring yielded an optically active gamma-lactam of protected alpha-quatemary serine derivative.

DOI： 10.1021/acs.joc.6b01722

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Language：English   Publisher：American Chemical Society  

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Language：English   Publisher：WILEY-V C H VERLAG GMBH  

Ruthenium-catalyzed annulation of 1-naphthylsilanes with internal alkynes afforded silaphenalenes through cleavage of the CH bond at the 8-position of the naphthalene. [RuH2(CO){P(p-FC6H4)(3)}(3)] efficiently catalyzed the reaction. The use of 1-naphthyldiphenylsilane as a substrate resulted in a better yield of the annulation product compared to the use of silanes with alkyl groups on the silicon atom. Internal alkynes with both aryl and alkyl groups were tolerated in this reaction.

DOI： 10.1002/chem.201502746

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Language：English   Publisher：AMER CHEMICAL SOC  

Rhodium-catalyzed copolymerization between 1,4-bis(acetylamino)benzene and diynes through C-H bond cleavage afforded pi-conjugated polymers containing benzodipyrrole moieties. The polymers with substituted benzene units exhibited nearly the same absorption peaks and HOMO levels. Fluorenone and benzothiadiazole moieties can be also introduced as electron-acceptor units to the main chain by polymerization in tert-amyl alcohol and tetrahydropyran as mixed solvent, leading to absorption at longer wavelength.

DOI： 10.1021/acsmacrolett.5b00343

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Language：English   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

PEPPSI-type Pd-complexes with the bulky mesoionic 1,2,3-triazolium carbenes (tzNHC) substituted by the adamantyl groups were prepared from 1-azidoadamantane and 1-ethynyladamantane. The X-ray analysis revealed that 1,4-diadamantyl-tzNHC complex (TAd-PEPPSI) showed longer Pd-C bond length than 1-adamantyl-4-phenyl-tzNHC complex (TAdPh-PEPPSI) and 1,4-diphenyl-tzNHC complex (TPh-PEPPSI). These complexes were applied to Hiyama coupling reaction between aryl bromides and phenyltrimethoxysilane. TAd-PEPPSI rapidly initiates the reaction, and TAdPh-PEPPSI gave good product yields. (C) 2015 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2015.01.040

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Language：English   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

The AgOAc/ThioClickFerrophos-complex catalyzed the 1,3-dipolar cycloaddition of 3,4-dihydropyrrole-2-carboxylates, a precursor of cyclic azomethine ylides, with N-substituted maleimide to give the exo-cycloadducts, that is, 7-azabicyclo[2.2.1]heptane-1-carboxylates, as the major product in moderate yields with a high enantiomeric excess (up to 86% ee) under the optimized conditions. Michael adducts were produced as a minor product. (C) 2014 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2014.09.070

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Language：English   Publisher：AMER CHEMICAL SOC  

Asymmetric domino allylstannylation-Heck reaction of o-formylaryl triflates was successively catalyzed by Pd/ClickFerrophos to give the 3-methylene-indan-1-ols in good yields with good to excellent enantioselectivities. The benefit of the reaction is that the starting o-formylaryl triflates are prepared from easily accessible salicylaldehyde derivatives, and the variation of the product, chiral 3-methylene-indan-1-ols, can be expanded. The reaction with 4-substituted substrates gave the corresponding 3-methylene-indan-1-ols in good yields with high enantioselectivities, whereas the reaction with 5- and 6-substituted substrates occasionally afforded the corresponding Stille coupling product in significant amounts along with the desired 3-methylene-indan-1-ols.

DOI： 10.1021/jo5010247

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Language：English   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

AgOAc/ThioClickFerrophos complex-catalyzed 1,3-dipolar cycloaddition of glycine imino ester, the precursor of azomethine ylide, with aryl- and alkylidene malonates afforded the corresponding exo-cycloadducts, that is, proline ester derivatives in high yields with high enantiomeric excess (up to 99% ee). The reactions proceeded smoothly under base-free conditions demonstrating the bifunctional catalysis of the silver complex. (C) 2014 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2013.12.101

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Language：English   Publisher：AMER CHEMICAL SOC  

The AgOAc/ThioClickFerrophos complex effectively catalyzed the conjugate addition of glycine imino esters to arylidene and alkylidene malonates, furnishing the corresponding adducts in good yields with high enantioselectivities, in the presence or absence of an external base. The complex also catalyzed conjugate addition to alpha-enones in the presence of 1,4-diazabicyclo[2.2.2]octane with high enantioselectivity, with formation of a small amount of cycloadducts.

DOI： 10.1021/ol4019584

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Language：English  

N-heterocyclic carbene (NHC) copper(I) complexes based on imidazol-2-ylidene and 1,2,3-triazol-5-ylidene catalyzed the direct C-H thiolation of benzothiazoles and benzoxazoles with aryl and alkyl thiols to give 2-aryl and 2-alkylthiobenzothiazoles in moderate-to-good yields. The NHC copper(I) complex [(IPr)CuI] was the most effective catalyst for the reaction among the NHC-Cu(I) complexes examined in this study. © 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2013.06.104

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Language：English   Publisher：GEORG THIEME VERLAG KG  

The copper(I) chloride catalyzed reaction of azides with alkynes in water at room temperature was promoted by the addition of a catalytic amount of 2-ethynylpyridine, affording the corresponding 1,4-disubstituted 1,2,3-triazoles in good yields after a specific reaction time. The catalytic system could be successfully applied to electron-rich, electron-poor, and sterically crowded substrates. A study of the additive effect of pyridine derivatives revealed that alkynyl and 2-pyridyl groups were essential for activating the copper catalyst.

DOI： 10.1055/s-0032-1318488

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Language：English   Publisher：AMER CHEMICAL SOC  

Nickel-catalyzed alkylative coupling of an enone or enal with methylenecyclopropane in the presence of triethylborane was achieved via stereospecific proximal C-C bond cleavage of methylenecyclopropane. With the use of methylenecyclopropane possessing an acyclic alkyl substituent, this reaction was also accompanied by the beta-hydrogen elimination.

DOI： 10.1021/ol303548x

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Language：Japanese   Publisher：中央大学理工学研究所  

CiNii Books

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A series of 1,2,3-triazol-5-ylidene (tzNHC) complexes of a (p-cymene)ruthenium system was synthesized. The reactivity of the N-bonded and C-bonded aryl groups in the tzNHC ligand was found to be significantly different with respect to intramolecular aromatic C-H bond activation. © 2013 The Royal Society of Chemistry.

DOI： 10.1039/c2dt32368k

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PubMed

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Language：English   Publisher：AMER CHEMICAL SOC  

We applied the combination of AgOAc with ThioClickFerrophos, the chiral ferrocenyl triazole-based P,S-ligand, to the reaction of glycine imino ester with nitroalkenes. The conjugate addition of the imino methyl ester preferentially produced anti-alpha-imino-gamma-nitrobutyrates in good yields with high enantioselectivities (ee) of up to 99% at -25 degrees C in THF in the presence of triethylamine. Meanwhile, the pyrrolidine cycloadducts were obtained as major products in good yields with high enantioselectivities (up to 96% ee) using tert-butyl imino ester in the absence of triethylamine at room temperature.

DOI： 10.1021/ol301916t

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Language：English   Publisher：AMER CHEMICAL SOC  

1,2,3-Triazol-5-ylidene copper(I) complexes (tzNHC-Cu) efficiently catalyzed the direct C-H carboxylation of benzoxazole and benzothiazole derivatives with CO2 to give the corresponding esters in excellent yields after treatment with alkyl iodide. The tzNHC copper(I) complex, i.e., [(TPr)CuCl], worked somewhat more effectively than the corresponding imidazol-2-ylidene copper(I) complex [(IPr)CuCl] to give the carboxylation product in higher yields.

DOI： 10.1021/ol301760n

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Language：English   Publisher：AMER CHEMICAL SOC  

The stereochemistry of the substitution of the alpha-dimethylamino group by dimethylzinc in the presence of acetyl chloride in the chiral benzylferrocene backbone was examined. The reaction with the benzylferrocene bearing an o-bromo substituent at both ferrocene and the phenyl ring proceeded with inversion of configuration, while the reaction with the benzylferrocene bearing an o-bromo substituent at either ferrocene or the phenyl ring proceeded with retention of configuration.

DOI： 10.1021/jo3012013

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Language：English   Publisher：AMER CHEMICAL SOC  

The first cross-reaction between a terminal silylacetylene and two ketene molecules leading to 1,3-enynes bearing a carboxylic ester group via double insertion of ketenes is achieved using a cationic rhodium complex catalyst. This reaction is applicable for various symmetrical and unsymmetrical ketenes with good stereoselectivities.

DOI： 10.1021/ol301897h

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Language：English   Publisher：WILEY-V C H VERLAG GMBH  

DOI： 10.1002/chem.201200271

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Language：English   Publisher：AMER CHEMICAL SOC  

Newly developed ClickFerrophos II ligands were applied in the hydrogenation of alpha,beta-unsaturated phosphonates. The use of a rhodium/ClickFerrophos II catalyst was examined in the hydrogenation of fimctionalized alpha,beta-unsaturated phosphonates and was revealed to be effective for beta-alkyl-beta-aryl or beta-dialkyl phosphonates, (Z)-beta-enolester phosphonates, and alpha-phenylethenyl phosphonates, producing the corresponding chiral phosphonates in good yields with high enantioselectivities (up to 96% ee).

DOI： 10.1021/jo300129m

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Language：English   Publisher：WILEY-V C H VERLAG GMBH  

A series of allyl 1,2,3-triazol-5-ylidene (tzNHC) palladium complexes was prepared, and the structures of the complexes were fully characterized by NMR and X-ray diffraction analyses. The donor properties of these ligands were evaluated by studying the vibrational spectra of their carbonyliridium complexes and their X-ray photoelectron spectra. These evaluations showed that the structures of the tzNHC palladium complexes are almost identical to those of the corresponding imidazole carbene palladium complexes, and that the tzNHC ligands have stronger donor properties than the imidazole carbene ligands. The relationship between catalytic activity and structure was examined by carrying out a room-temperature SuzukiMiyaura coupling reaction, and the cinnamylpalladium complex bearing 1,4-bis(2,6-diisopropylphenyl)-3-methyl-1,2,3-triazol-5-ylidene (TPr) was found to be the most active catalyst. (cinnamyl)(TPr)PdCl showed high activity in the room-temperature reaction performed with aryl chlorides regardless of the electronic and steric properties of the substituents, and was effective in reactions with sterically crowded arylboronic acids.

DOI： 10.1002/ejic.201101383

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Highly diastereoselective reductive coupling reaction was achieved between an aldehyde and a norbomene to afford an alcohol compound using a nickel/phosphine catalyst system in the presence of a reducing agent. The combination of a PCy3 ligand and triethylborane as the reducing agent proved effective for the reaction. A wide range of aldehydes were found to participate in the reaction with high diastereoselectivities.

DOI： 10.1246/cl.2012.157

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Language：Japanese   Publisher：有機合成化学協会  

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Language：Japanese   Publishing type：Book review, literature introduction, etc.  

The studies on nickel(0)-catalyzed three-component reactions via C-H and C-C bond activation were described. Highly regio-and stereoselective cross-trimerization of alkynes proceeded to give the corresponding 1,3-diene-5-yne by combination of triisopropylsilylacetylene and identical or distinct two alkynes via selective terminal C-H bond activation of triisopropylsilylacetylene in the presence of Ni(cod) 2/phosphine catalyst. The methodology could be also extended toward the three-component reaction among two alkynes and a norbornene to give the 1,5-enyne. On the other hand, our interest also focused on three-component reductive coupling reaction between ring-strained cyclic alkene, aryl aldehyde and silane. Using methylenecyclopropane, reductive coupling reaction with aryl aldehyde and triisopropylsilane proceeded to yield silylated allylic alcohols via C-C bond cleavage of methylenecyclopropane ring in the presence of Ni(cod) 2/NHC catalyst. We also found an unprecedented three-component reductive coupling via aromatic C-H bond activation of aryl aldehyde at the ortho position by combination with norbornene and triisopropylsilane leading to silylated indanol using Ni(cod) 2/NHC catalyst.

DOI： 10.5059/yukigoseikyokaishi.70.2

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The bis-1,4-dimesityl-1,2,3-triazol-5-ylidene palladium complex (1a) successfully catalyzes the Mizoroki Heck and Sonogashira coupling reactions with aryl bromides to give the corresponding alkenes and alkynes, respectively, in good to excellent yields. In the Mizoroki-Heck reaction, electron-rich, electron-poor, and functionalized aryl bromides and alkenes are tolerated, while the substrates are limited to electron-poor aryl halides in the Sonogashira coupling reaction. The palladium complex also catalyzes cross-coupling reactions with aryl chlorides to give higher yields of products than does the bis-IMes-Pd complex analogue (2), under specific conditions. (C) 2011 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2011.07.045

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Language：English   Publisher：AMER CHEMICAL SOC  

The AgOAc/ThioClicicFerrophos complex catalyzed the asymmetric Mannich reaction of glycine Schiff base with N-tosylimines effectively to give a mixture of syn and anti adducts (syn/anti = 60/40-70/30) at high yields with high enantioselectivities (up to 98% ee). The complex also catalyzed the asymmetric amination of glycine Schiff base with di-tert-butyl azodicarboxylate with high enantioselectivity.

DOI： 10.1021/jo2003727

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Complexes of copper with 1,4-diphenyl, 1,4-dimesityl, and 1-(2,6-diisopropylphenyl)-4-(3,5-xylyl)-1,2,3-triazol-5-ylidene (abnormal NHC = N-heterocyclic carbene) were prepared by consecutive treatment of the corresponding azolium salts with silver oxide and copper chloride. The new CuCl(aNHC) complexes efficiently catalyzed click reactions of azides with alkynes to give 1,4-substituted 1,2,3-triazoles in excellent yields at room temperature with short reaction times. CuCl(TPh) was particularly effective for the reaction between sterically hindered azides and alkynes.

DOI： 10.1021/ol102858u

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Language：English   Publisher：AMER CHEMICAL SOC  

The highly chemo-, regio-, and stereoselective three-component cross-trimerization reaction between triisopropylsilylacetylene, diarylacetylene, and a terminal alkyne was achieved by Ni(cod)(2)/P(p-CF3C6H4)(3) catalyst at room temperature via selective C-H oxidative addition of the terminal silylacetylene. The reaction is applicable for various diarylacetylenes and terminal alkynes to yield the corresponding 1,3-diene-5-yne compounds.

DOI： 10.1021/ol102687p

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A nickel-catalyzed three-component coupling between methylenecyclopropane, aldehydes, and silanes afforded silylated allylic alcohols that possess an alkyl substituent at the 2-position via cleavage of the proximal C-C bond of methylenecyclopropane

DOI： 10.1021/ol101838q

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A silver(I)/ThioClickFerrophos complex catalyzed the endo selective asymmetric 1,3-dipolar cycloaddition reaction of methyl N-benzylideneglycinate (the source of azomethine ylides) with alpha,beta-unsaturated esters and maleimides to give the endo-2,4,5- and 2,3,4,5-substituted pyrrolidines in good yields with high enantioselectivities (up to 99% ee). The complex also effectively catalyzed the endo selective reactions with beta-nitrostyrene to give the 4-nitropyrrolidine in a high enantioselectivity. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2010.07.085

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：AMER CHEMICAL SOC  

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：AMER CHEMICAL SOC  

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Language：English   Publisher：ELSEVIER SCIENCE SA  

New methylnaphthalene-linked imidazolium salts 1 were synthesized through the reaction of 1,8-dibromomethylnaphthalene and N-alkylimidazole. On treatment of imidazolium salt 1 with silver oxide followed by [Cp*MCl(2)](2) (M = Ir, Rh), binuclear iridium and rhodium complexes 2 were formed. Reaction of these complexes 2 with AgPF(6) afforded Cl-bridged cationic binuclear iridium and rhodium complexes 3. X-ray crystallographic analysis of 3 revealed that the two imidazole rings of the carbene ligand are in a parallel geometry. The cationic binuclear iridium complexes 3-Ir could be applied to the intramolecular hydroamination reaction of 2-ethynylaniline to give the corresponding indole compound. (C) 2010 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jorganchem.2010.04.006

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A silver(I)/ThioClickFerrophos complex catalyzed the highly endo-selective asymmetric 1,3-dipolar cycloaddition reaction of methyl N-benzylideneglycinate (the source of azomethine ylides) with (E)-acyclic alpha-enones having an endolexo ratio of 90/10 to 99/1. The highly functionalized endo-4-acyl pyrrolidines were obtained in good yields with high enantioselectivities (up to 98% ee). The complex also effectively catalyzed endo-selective reactions with 2-cyclopentenone to give the endo-bicyclic pyrrolidine in high enantioselectivity.

DOI： 10.1021/ol100336q

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Language：English   Publisher：AMER CHEMICAL SOC  

A silver(I)/ThioClickFerrophos complex catalyzed the highly endo-selective asymmetric 1,3-dipolar cycloaddition reaction of methyl N-benzylideneglycinate (the source of azomethine ylides) with (E)-acyclic alpha-enones having an endolexo ratio of 90/10 to 99/1. The highly functionalized endo-4-acyl pyrrolidines were obtained in good yields with high enantioselectivities (up to 98% ee). The complex also effectively catalyzed endo-selective reactions with 2-cyclopentenone to give the endo-bicyclic pyrrolidine in high enantioselectivity.

DOI： 10.1021/ol100336q

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Language：English   Publisher：AMER CHEMICAL SOC  

The first three-component reaction of norbornene with two alkynes leading to 1,5-enyne via C-H bond activation of terminal silylacetylene was achieved using a Ni(cod)(2)/phosphine catalyst. This reaction is applicable for various Internal alkynes and norbornene derivatives with high regio- and stereoselectivities.

DOI： 10.1021/ol9025556

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Language：Japanese   Publisher：Wiley-VCH  

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CiNii Books

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A copper(I)/ClickFerrophos complex catalyzed the asymmetric 1,3-dipolar cycloaddition reaction of methyl N-benzylideneglycinate (the source of azomethine ylides) with vinyl sulfone to give the exo-2,4,5-trisubstituted pyrrolidine in good yield with high enantioselectivity (99% ee). The complex also effectively catalyzed reactions of other dipolarophiles such as acrylates, maleate, and maleimides to give the exo-2,4,5-, and 2,3,4,5-substituted pyrrolidine derivatives with high diastereo- and enantioselectivities.

DOI： 10.1021/ol8003996

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Language：English   Publisher：AMER CHEMICAL SOC  

A copper(I)/ClickFerrophos complex catalyzed the asymmetric 1,3-dipolar cycloaddition reaction of methyl N-benzylideneglycinate (the source of azomethine ylides) with vinyl sulfone to give the exo-2,4,5-trisubstituted pyrrolidine in good yield with high enantioselectivity (99% ee). The complex also effectively catalyzed reactions of other dipolarophiles such as acrylates, maleate, and maleimides to give the exo-2,4,5-, and 2,3,4,5-substituted pyrrolidine derivatives with high diastereo- and enantioselectivities.

DOI： 10.1021/ol8003996

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Scandium(III) triflate smoothly catalyzed the reaction of imines with ethyl propiolate (2.5 equiv) to produce the corresponding N-substituted 1,4-dihydropyridines in good yields in toluene or BTF under reflux conditions. It also catalyzed the reaction of aniline and ethyl propiolate (3.2 equiv) to give another 1,4-dihydropyridine bearing three ester groups in moderate yield under the same conditions. (c) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2007.11.003

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Scandium(III) triflate smoothly catalyzed the reaction of imines with ethyl propiolate (2.5 equiv) to produce the corresponding N-substituted 1,4-dihydropyridines in good yields in toluene or BTF under reflux conditions. It also catalyzed the reaction of aniline and ethyl propiolate (3.2 equiv) to give another 1,4-dihydropyridine bearing three ester groups in moderate yield under the same conditions. (c) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2007.11.003

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The new ferrocenyl P,P- and P,N-ligands 5 and 6 (collectively, '' ClickFerrophos '') were readily prepared in four steps using Click Chemistry methodology, starting from the commercially available aminoferrocene 1. Rhodium and ruthenium complexes of ClickFerrophos 5 were effective catalysts for the hydrogenation of alkenes and ketones, respectively, producing products with up to 99.7% ee. The analogous palladium complex with 6 worked well for asymmetric allylic alkylation.

DOI： 10.1021/ol702519f

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Language：English   Publisher：AMER CHEMICAL SOC  

The new ferrocenyl P,P- and P,N-ligands 5 and 6 (collectively, '' ClickFerrophos '') were readily prepared in four steps using Click Chemistry methodology, starting from the commercially available aminoferrocene 1. Rhodium and ruthenium complexes of ClickFerrophos 5 were effective catalysts for the hydrogenation of alkenes and ketones, respectively, producing products with up to 99.7% ee. The analogous palladium complex with 6 worked well for asymmetric allylic alkylation.

DOI： 10.1021/ol702519f

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Language：English   Publisher：WILEY-V C H VERLAG GMBH  

Homoannularly bridged ferrocene 6b was prepared by intramolecular coupling of 1,5-dilithioferrocene 5b mediated by Fe(acac)(3). Dilithioferrocene 5b was prepared by lithium-halogen exchange of the corresponding diiodide, which was prepared by 1,5-dilithiation of the o-TMS-blocked ferrocene and followed by trapping with iodine and removal of the TMS group. Alternatively, 5b could be readily prepared by the reaction of o-bromophenylferrocene 8 with nBuLi (> 2 equiv.). The benzene ring of 6b underwent ortho lithiation with tBuLi, and the resulting lithiated species was trapped with Ph2PCl to produce corresponding aminophosphane 7d. Arninophosphane 13, which has the phosphanyl group on the cyclopentarlienyl ring, was prepared by intramolecular coupling of 1,5-dilithiated PhPPFA 11 mediated by Fe(acac)3. New N,P ligands 7d and 13 were used in the palladium-catalyzed allylic alkylation and amination of 1,3-diphenyl-2-propenyl acetate (14), and ligand 7d was found to give good yields with enantioselectivities as high as 96 % ee.

DOI： 10.1002/ejoc.200700470

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Language：English   Publisher：WILEY-V C H VERLAG GMBH  

Homoannularly bridged ferrocene 6b was prepared by intramolecular coupling of 1,5-dilithioferrocene 5b mediated by Fe(acac)(3). Dilithioferrocene 5b was prepared by lithium-halogen exchange of the corresponding diiodide, which was prepared by 1,5-dilithiation of the o-TMS-blocked ferrocene and followed by trapping with iodine and removal of the TMS group. Alternatively, 5b could be readily prepared by the reaction of o-bromophenylferrocene 8 with nBuLi (> 2 equiv.). The benzene ring of 6b underwent ortho lithiation with tBuLi, and the resulting lithiated species was trapped with Ph2PCl to produce corresponding aminophosphane 7d. Arninophosphane 13, which has the phosphanyl group on the cyclopentarlienyl ring, was prepared by intramolecular coupling of 1,5-dilithiated PhPPFA 11 mediated by Fe(acac)3. New N,P ligands 7d and 13 were used in the palladium-catalyzed allylic alkylation and amination of 1,3-diphenyl-2-propenyl acetate (14), and ligand 7d was found to give good yields with enantioselectivities as high as 96 % ee.

DOI： 10.1002/ejoc.200700470

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Language：English   Publisher：GEORG THIEME VERLAG KG  

A Lewis acid effectively catalyzed the three-cornponent coupling reaction of an aromatic amine and aldehyde with ethyl propiolate, and the 2,3-disubstituted quinoline was regioselectively obtained in a good yield (up to 83% GC yield).

DOI： 10.1055/s-2007-991058

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Language：English   Publisher：GEORG THIEME VERLAG KG  

Copper(II) triflate doubly catalyzed the substitution of benzylic acetates by TMSN3 and the subsequent 1,3-dipolar addition with an alkyne in one pot. This procedure afforded the preparation of 1,4-disubstituted 1,2,3-triazoles in good yields starting from the easily accessible acetates without isolating an organic azide using a single catalyst.

DOI： 10.1055/s-2007-986638

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Language：Japanese   Publisher：中央大学理工学研究所  

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(Chemical Equation Presented) The 1,5-dilithiation of o-TMS blocked (dimethylamino)phenylmethylferrocene 4 unexpectedly occurred even though one equimolar amount of t-BuLi was used and the 1,5-dilithiated ferrocene 6 was trapped by iodine followed by removal of the TMS group to give the 1,5-diiodoferrocene 11 in a reasonable yield. The 1,5-diiodoferrocene 11 was converted into the diastereomer of Taniaphos 12 by sequential dilithiation and trapping with Ph2PCl. The rhodium and copper complex of 12 catalyzed well the asymmetric allylic alkylation with a Grignard reagent and hydrogenation with the α-acetamidocinnamic acid ester, respectively, with high enantioselectivities. The methoxy 1,5-diphosphane 14, of which the enantiomer is known as a good ligand for the rhodium-catalyzed asymmetric hydrogenation, was obtained by the inversive substitution of the dimethylamino group of 11 by NaOMe and subsequent dilithiation and trapping with Ph2PCl. © 2007 American Chemical Society.

DOI： 10.1021/jo062210l

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Language：English   Publisher：AMER CHEMICAL SOC  

The 1,5-dilithiation of o-TMS blocked (dimethylamino)phenylmethylferrocene 4 unexpectedly occurred even though one equimolar amount of t-BuLi was used and the 1,5-dilithiated ferrocene 6 was trapped by iodine followed by removal of the TMS group to give the 1,5-diiodoferrocene 11 in a reasonable yield. The 1,5-diiodoferrocene 11 was converted into the diastereomer of Taniaphos 12 by sequential dilithiation and trapping with Ph2PCl. The rhodium and copper complex of 12 catalyzed well the asymmetric allylic alkylation with a Grignard reagent and hydrogenation with the alpha-acetamidocinnamic acid ester, respectively, with high enantioselectivities. The methoxy 1,5-diphosphane 14, of which the enantiomer is known as a good ligand for the rhodium-catalyzed asymmetric hydrogenation, was obtained by the inversive substitution of the dimethylamino group of 11 by NaOMe and subsequent dilithiation and trapping with Ph2PCl.

DOI： 10.1021/jo0622101

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Language：English   Publisher：GEORG THIEME VERLAG KG  

An efficient cross-coupling reaction of diphenyl disulfide or diselenide with substituted aryl bromides using PdCl2(dppf) and zinc has been developed. This method gave functionalized unsymmetrical aryl sulfides and selenides in good to excellent yields under neutral conditions.

DOI： 10.1055/s-2006-949607

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Language：English   Publisher：GEORG THIEME VERLAG KG  

The asymmetric conjugate addition of 0-benzylhydroxylamine to alpha,beta-unsaturated 3-acyloxazolidin-2-ones was smoothly catalyzed by the Sc(OTf)(3)/2,6-bis[(S)-4-isopropyloxazolin-2-yl]pyridine (i-Pr-pybox) complex in the presence of MS 4 A to give the corresponding beta-amino acids in good conversions with high enantioselectivities (up to 91% ee).

DOI： 10.1055/s-2006-939068

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Language：English   Publisher：WILEY-V C H VERLAG GMBH  

The treatment of (R,R)-1,2-bis(1-acetoxy-1-phenylmethyl)ferrocene (1) with azidotrimethylsilane in CH2Cl2 in the presence of a catalytic amount of a Lewis acid such as Cu(OTf)(2) or Sc(OTf)(3), at -40 degrees C for 24 h, gives a mixture of two diastereomeric ferrocenyl diazides 4 and 5 in an 80:20 ratio. The major isomer (R,R)-4 is formed with retention of configuration at both benzylic chiral centers whereas the minor isomer meso- (R, S) -5 is formed with inversion of configuration at one of the two chiral centers. After a shorter reaction time (12 h), the (R,R)-ferrocenylazido acetate 6 was isolated as a single diastereomer, which gave 4 and 5 under the same conditions with almost the same ratio as with the longer reaction time. These results show that the first step of the reaction is the substitution, with retention of configuration, of the exo acetate of 1 by means of an iron-assisted ionization, i.e., neighboring-group participation, then the endo acetate is replaced by the azide ion with retention or inversion of configuration to give 4 or 5, respectively. The optically active complex 4 could be converted into the corresponding ferrocenyldiamme 2 by reduction with LiAIH(4), and its ditosylamide 8a and di-acetamide 8b were isolated as stable compounds. The ferrocenyldiamine and both diamides were used as ligands in the ruthenium-catalyzed asymmetric transfer hydrogenation of aryl ketones, and the complex with 2 gave 1-arylethanols in good yields with up to 75% ee. (c) Wiley-VCH Verlag GmbH & Co.

DOI： 10.1002/ejoc.200500660

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Language：English   Publisher：WILEY-V C H VERLAG GMBH  

The treatment of (R,R)-1,2-bis(1-acetoxy-1-phenylmethyl)ferrocene (1) with azidotrimethylsilane in CH2Cl2 in the presence of a catalytic amount of a Lewis acid such as Cu(OTf)(2) or Sc(OTf)(3), at -40 degrees C for 24 h, gives a mixture of two diastereomeric ferrocenyl diazides 4 and 5 in an 80:20 ratio. The major isomer (R,R)-4 is formed with retention of configuration at both benzylic chiral centers whereas the minor isomer meso- (R, S) -5 is formed with inversion of configuration at one of the two chiral centers. After a shorter reaction time (12 h), the (R,R)-ferrocenylazido acetate 6 was isolated as a single diastereomer, which gave 4 and 5 under the same conditions with almost the same ratio as with the longer reaction time. These results show that the first step of the reaction is the substitution, with retention of configuration, of the exo acetate of 1 by means of an iron-assisted ionization, i.e., neighboring-group participation, then the endo acetate is replaced by the azide ion with retention or inversion of configuration to give 4 or 5, respectively. The optically active complex 4 could be converted into the corresponding ferrocenyldiamme 2 by reduction with LiAIH(4), and its ditosylamide 8a and di-acetamide 8b were isolated as stable compounds. The ferrocenyldiamine and both diamides were used as ligands in the ruthenium-catalyzed asymmetric transfer hydrogenation of aryl ketones, and the complex with 2 gave 1-arylethanols in good yields with up to 75% ee. (c) Wiley-VCH Verlag GmbH & Co.

DOI： 10.1002/ejoc.200500660

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Language：English   Publisher：JOHN WILEY & SONS INC  

We prepared a series of mono and bis ortho-aminoalkyl-substituted chiral trichalcogena[3]-ferrocenophanes by dilithiation of mono- and bis-aminoferrocenes and subsequent reaction with sulfur and selenium in moderate yields. The X-ray crystallographic analyses of triselena[3]ferrocenophanes revealed that the bridge selenium atom was directed toward to the ortho-substituent (endo). In the bis-type ferrocenophanes, bridge inversion was not detected by H-1 NMR because they would be homomeric. (c) 2006 Wiley Periodicals, Inc.

DOI： 10.1002/hc.20189

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The pinacol coupling reaction of planar chiral ortho-oxazoline-substituted formylferrocene was smoothly mediated by Sml(2) or Sm(OTf)(3) to give the (R,R) isomer selectivity (up to 76% diastereomeric excess). The combination of Yb(OTf)(3) and the (R,R)-ferrocenyl diol was revealed to be a good catalyst for the asymmetric Diels-Alder reaction of 3-acyloxazolidinone with cyclopentadiene, and the endo adduct was produced in up to 80% enantiomeric excess.

DOI： 10.1021/ol0523291

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The treatment of (1-R,4R)-1,2-bis(phenylmethyl)ferrocenyl diacetate 2a with aqueous ammonium in THF/MeOH at room temperature for 18 h gave the single diastereomer of the (1R,4R,Sp)-1,2-acetoamido alcohol 4a with retention of the configuration. This result showed that the aminolysis occurred regioselectively at one side of the two acetates. Similarly, hydrolysis of the diacetate 2a at room temperature for 18 h occurred regio- and stereoselectively to give the optically active half-ester 10 in a good yield. The ease of the substitution may depend on the geometry of the two stereogenic centers. Only one of the acetoxy groups is suitably aligned for ionization (exo to the ferrocenyl group) to proceed efficiently; the aminolysis takes place smoothly by iron-assisted ionization, i.e., neighboring group participation. The leaving group on the second acetoxy group is not suitably aligned (endo, to the ferrocenyl group) and also cannot undergo a conformational change for it to adopt the appropriate orientation for ionization to occur. This reaction is the first case of substitution in a chiral molecule in which a conformational difference between two leaving groups happened to affect the rate of aminolysis and hydrolysis at two stereogenic centers.

DOI： 10.1021/jo049386c

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The treatment of (1-R,4R)-1,2-bis(phenylmethyl)ferrocenyl diacetate 2a with aqueous ammonium in THF/MeOH at room temperature for 18 h gave the single diastereomer of the (1R,4R,Sp)-1,2-acetoamido alcohol 4a with retention of the configuration. This result showed that the aminolysis occurred regioselectively at one side of the two acetates. Similarly, hydrolysis of the diacetate 2a at room temperature for 18 h occurred regio- and stereoselectively to give the optically active half-ester 10 in a good yield. The ease of the substitution may depend on the geometry of the two stereogenic centers. Only one of the acetoxy groups is suitably aligned for ionization (exo to the ferrocenyl group) to proceed efficiently; the aminolysis takes place smoothly by iron-assisted ionization, i.e., neighboring group participation. The leaving group on the second acetoxy group is not suitably aligned (endo, to the ferrocenyl group) and also cannot undergo a conformational change for it to adopt the appropriate orientation for ionization to occur. This reaction is the first case of substitution in a chiral molecule in which a conformational difference between two leaving groups happened to affect the rate of aminolysis and hydrolysis at two stereogenic centers.

DOI： 10.1021/jo049386c

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Language：English   Publisher：WILEY-V C H VERLAG GMBH  

The reduction of ketones and aldehydes with lanthanide metals (La, Ce, Sm, Yb) and a catalytic amount of iodine (5 mol %) in iPrOH proceeded smoothly to produce the corresponding alcohols as the major products in good yield, while in THF, methanol, and ethanol the pinacols were mainly produced. The yields of alcohols were improved most effectively by the use of Sm metal, the amount of pinacol produced thus being minimized. The actual reducing agent may be samarium isopropyloxide, which mediates the Meerwein-Ponndorf-Verley-type hydride-transfer reaction, since the reaction can be carried out catalytically with respect to samarium. The stereoselectivities of the reductions of the 2- and 4-substituted cyclohexanones with Sm/iPrOH were higher than those achieved with SmI2/iPrOH or Sm/H2O. The asymmetric reduction of acetophenone could be achieved to give the 1-phenylethanol in up to 95 % ee in the presence of the chiral ligand 7. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.

DOI： 10.1002/ejoc.200400030

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Language：English   Publisher：WILEY-V C H VERLAG GMBH  

The reduction of ketones and aldehydes with lanthanide metals (La, Ce, Sm, Yb) and a catalytic amount of iodine (5 mol %) in iPrOH proceeded smoothly to produce the corresponding alcohols as the major products in good yield, while in THF, methanol, and ethanol the pinacols were mainly produced. The yields of alcohols were improved most effectively by the use of Sm metal, the amount of pinacol produced thus being minimized. The actual reducing agent may be samarium isopropyloxide, which mediates the Meerwein-Ponndorf-Verley-type hydride-transfer reaction, since the reaction can be carried out catalytically with respect to samarium. The stereoselectivities of the reductions of the 2- and 4-substituted cyclohexanones with Sm/iPrOH were higher than those achieved with SmI2/iPrOH or Sm/H2O. The asymmetric reduction of acetophenone could be achieved to give the 1-phenylethanol in up to 95 % ee in the presence of the chiral ligand 7. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.

DOI： 10.1002/ejoc.200400030

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The rare earth(III) salt catalysed asymmetric Diels-Alder reaction of cyclopentadiene with a chiral dienophile in supercritical carbon dioxide (scCO(2)) proceeded rapidly to give the adduct with a higher diastereoselectivity than that in dichloromethane; Yb(ClO4)(3) gave the endo adduct with value up to 77% de at 40degreesC, 8 MPa. The chiral rare earth diketonate catalyzed hetero Diels-Alder reaction of the Danishefsky's diene with benzaldehyde gave a higher yield and an enantioselectivity in scCO(2) than that in dichloromethane. Scandium/pybox 8a complex catalysed asymmetric Diels-Alder reaction of 3-crotonoyl-2-oxazolidinone with cyclopentadiene in the presence of MS4A proceeded smoothly in scCO(2) to give the endo adduct 10 in a good yield with up to 88% ee. (C) 2003 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2003.04.009

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The rare earth(III) salt catalysed asymmetric Diels-Alder reaction of cyclopentadiene with a chiral dienophile in supercritical carbon dioxide (scCO(2)) proceeded rapidly to give the adduct with a higher diastereoselectivity than that in dichloromethane; Yb(ClO4)(3) gave the endo adduct with value up to 77% de at 40degreesC, 8 MPa. The chiral rare earth diketonate catalyzed hetero Diels-Alder reaction of the Danishefsky's diene with benzaldehyde gave a higher yield and an enantioselectivity in scCO(2) than that in dichloromethane. Scandium/pybox 8a complex catalysed asymmetric Diels-Alder reaction of 3-crotonoyl-2-oxazolidinone with cyclopentadiene in the presence of MS4A proceeded smoothly in scCO(2) to give the endo adduct 10 in a good yield with up to 88% ee. (C) 2003 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2003.04.009

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Language：English   Publisher：AMER CHEMICAL SOC  

The reaction of (C5Me5)(2)Sm(THF)(2) with 2 equiv of benzophenone imine (Ph2C=NH) in THF at room temperature gave the samarocene(III) amine/ketimido complex (C5Me5)(2)Sm(N=CPh2)(NH2CHPh2) (1) in 58% isolated yield. The use of 1 equiv of Ph2C=NH also afforded 1 as the only isolable product, albeit in a lower yield (ca. 20%). Deuterium-labeling experiments suggest that 1 is formed via hydrogen abstraction by the in-situ-generated imine radical anion species, followed by acid-base reaction between the resulting amido species and another molecule of Ph2C=NH. The reactions of 2 equiv of Sm(OAr)(2)(THF)(3) (Ar = (C6H2Bu2)-Bu-t-2,6-Me-4) with N-phenyl benzophenone imine (Ph2C=NPh) and N-phenyl fluorenone imine (C12H8C=NPh) yielded the Sm(III) eta(2)-imine-dianion/aryloxide complexes Sm(eta(2)-Ph-2-CNPh)(OAr)(THF)(3) (3, 65%) and Sm(eta(2)-C12H8CNPh)(OAr)(THF)(3) (4, 77%), respectively, together with the byproduct Sm(OAr)(3). The reaction of 1 equiv of Sm(OAr)(2)(THF)(3) with Ph2C=NPh also gave the imine-dianion complex 3, whereas an imine radical anion species was not observed. Similarly, the reactions of 2 equiv of SmtN(SiMe3)(2)}(2)(THF)(2) with Ph-2-C=NPh and C12H8C=NPh yielded the q2-imine-dianion/silylamido complexes Sm(eta(2)-(PhCNPh)-C-2){N(SiMe3)(2)}(THF)(3) (5, 87%) and Sm(eta(2)-C12H8CNPh){N(SiMe3)(2)}(THF)(3) (6, 71%), respectively. Complexes 3-6 represent the first examples of structurally characterized trivalent lanthanide eta(2)-imine complexes.

DOI： 10.1021/om030366v

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The reaction of (C5Me5)(2)Sm(THF)(2) with 2 equiv of benzophenone imine (Ph2C=NH) in THF at room temperature gave the samarocene(III) amine/ketimido complex (C5Me5)(2)Sm(N=CPh2)(NH2CHPh2) (1) in 58% isolated yield. The use of 1 equiv of Ph2C=NH also afforded 1 as the only isolable product, albeit in a lower yield (ca. 20%). Deuterium-labeling experiments suggest that 1 is formed via hydrogen abstraction by the in-situ-generated imine radical anion species, followed by acid-base reaction between the resulting amido species and another molecule of Ph2C=NH. The reactions of 2 equiv of Sm(OAr)(2)(THF)(3) (Ar = (C6H2Bu2)-Bu-t-2,6-Me-4) with N-phenyl benzophenone imine (Ph2C=NPh) and N-phenyl fluorenone imine (C12H8C=NPh) yielded the Sm(III) eta(2)-imine-dianion/aryloxide complexes Sm(eta(2)-Ph-2-CNPh)(OAr)(THF)(3) (3, 65%) and Sm(eta(2)-C12H8CNPh)(OAr)(THF)(3) (4, 77%), respectively, together with the byproduct Sm(OAr)(3). The reaction of 1 equiv of Sm(OAr)(2)(THF)(3) with Ph2C=NPh also gave the imine-dianion complex 3, whereas an imine radical anion species was not observed. Similarly, the reactions of 2 equiv of SmtN(SiMe3)(2)}(2)(THF)(2) with Ph-2-C=NPh and C12H8C=NPh yielded the q2-imine-dianion/silylamido complexes Sm(eta(2)-(PhCNPh)-C-2){N(SiMe3)(2)}(THF)(3) (5, 87%) and Sm(eta(2)-C12H8CNPh){N(SiMe3)(2)}(THF)(3) (6, 71%), respectively. Complexes 3-6 represent the first examples of structurally characterized trivalent lanthanide eta(2)-imine complexes.

DOI： 10.1021/om030366v

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Several bisimine and diol-based chiral ligands were examined as scandium(Ill) triflate complexes in the asymmetric Diels-Alder reaction of cyclopentadiene (2) with 3-acryloyloxazolidin-2-one (1) in the presence of 2,6-lutidine: the scandium/salen complex was revealed to be the most effective catalyst, which afforded the endo adduct in a good yield with 85% ee. Addition of a tertiary amine, such as 2,6-lutidine, was critical to achieve high enantioselectivity; enantioselectivity was remarkably decreased in the absence of the amine. (C) 2003 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0040-4039(03)00674-9

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Several bisimine and diol-based chiral ligands were examined as scandium(Ill) triflate complexes in the asymmetric Diels-Alder reaction of cyclopentadiene (2) with 3-acryloyloxazolidin-2-one (1) in the presence of 2,6-lutidine: the scandium/salen complex was revealed to be the most effective catalyst, which afforded the endo adduct in a good yield with 85% ee. Addition of a tertiary amine, such as 2,6-lutidine, was critical to achieve high enantioselectivity; enantioselectivity was remarkably decreased in the absence of the amine. (C) 2003 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0040-4039(03)00674-9

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The samarium(II) iodide mediated reaction of N,N-dibenzyl-protected (S)-alpha-amino aldehydes with (1S,2R)-N-methylephedrinyl acrylate gave the (4R,1'S)-gamma-(aminoalkyl)-gamma-butyrolactones in good yields with high diastereoselectivities (up to 80% de); (4R,1'S)-gamma-amino-(2-phenylethyl)-gamma-butyrolactone (6a), which should be a potent precursor for gamma-secretase inhibitors, was obtained with high de value.

DOI： 10.1021/jo020574h

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The samarium(II) iodide mediated reaction of N,N-dibenzyl-protected (S)-alpha-amino aldehydes with (1S,2R)-N-methylephedrinyl acrylate gave the (4R,1'S)-gamma-(aminoalkyl)-gamma-butyrolactones in good yields with high diastereoselectivities (up to 80% de); (4R,1'S)-gamma-amino-(2-phenylethyl)-gamma-butyrolactone (6a), which should be a potent precursor for gamma-secretase inhibitors, was obtained with high de value.

DOI： 10.1021/jo020574h

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Language：Japanese   Publisher：Society of Synthetic Organic Chemistry  

A classical route to chiral ferrocenes is optical resolution of the racemate and limited compounds have been prepared by this method. Recent successes in the synthesis of a variety of chiral ferrocenes without optical resolution now have attracted considerable attention in asymmetric synthesis. The chiral ferrocenylalcohols, -amines, -acetals, and -oxazolines can be readily prepared from achiral acyl-, formylferrocenes, and ferrocenecarboxylic acids. These substituents attached to cyclopentadienyl group of ferrocenes are strong ortho directing groups which lead to planar chiral ferrocenes with highly regioselection (&gt
99% de). The planar chiral ferrocene can be also prepared by enantioselective lithiation of the achiral ferrocenylamide and amine with the chiral lithium reagent. C2 symmetrical 1, 1′-ferrocenediol is obtained from asymmetric reduction of 1, 1′-diacyl ferrocene and can be converted to the corresponding ferrocenediamine and -diphosphine derivatives. New planar chiral ferrocenyl phosphines and alcohols are examined in the benchmark asymmetric allylic substitution and dialkylzinc addition to an aldehyde, respectively.

DOI： 10.5059/yukigoseikyokaishi.61.211

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Language：Japanese   Publisher：中央大学理工学研究所  

CiNii Books

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Enantioselective borohydride reduction, catalyed by the optically active beta-ketoiminato cobalt(II) complex, was successfully applied to the 1,1'-dialkanoyl- and 1,1'-dibenzoylferrocenes to afford the corresponding C-2-symmetrical chiral ferrocenyl diols with high diastereoselectivity and excellent enantioselectivity.

DOI： 10.1021/ol0266018

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The reaction between (±)-2-arylpropanoyl chlorides 1 (2 equiv.) and enantiopure N-trimethylsilyloxazolidin-2-one 2 in the presence of a catalytic amount of CuCl2 in hexane affords the corresponding N-acyloxazolidin-2-one in good chemical yields (97%) with up to 50% de. © 2002 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0957-4166(02)00409-3

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The reaction between (+/-)-2-arylpropanoyl chlorides 1 (2 equiv.) and enantiopure N-trimethylsilyoxazolidin-2-one 2 in the presence of a catalytic amount of CuCl2 in hexane affords the corresponding N-acyloxazolidin-2-one in good chemical yields (97%) with up to 50% de. (C) 2002 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0957-4166(02)00409-3

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[GRAPHICS]
The Sc(OTf)(3)/FERRODIOL (2) complex was prepared at -78degreesC in CH2Cl2 in the presence of 2,6-lutidine and MS 4A. The chiral scandium Lewis acid-catalyzed asymmetric Diels-Alder reaction of cyclopentadiene (3) with 3-acyloxazolidin-2-ones (4) effectively produced the adduct (5) in a high yield with good selectivity, i.e., endo/exo = 90:10 up to 91% ee (endo).

DOI： 10.1021/ol0171766

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Language：English   Publisher：AMER CHEMICAL SOC  

[GRAPHICS]
The Sc(OTf)(3)/FERRODIOL (2) complex was prepared at -78degreesC in CH2Cl2 in the presence of 2,6-lutidine and MS 4A. The chiral scandium Lewis acid-catalyzed asymmetric Diels-Alder reaction of cyclopentadiene (3) with 3-acyloxazolidin-2-ones (4) effectively produced the adduct (5) in a high yield with good selectivity, i.e., endo/exo = 90:10 up to 91% ee (endo).

DOI： 10.1021/ol0171766

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Language：English   Publisher：GEORG THIEME VERLAG KG  

The rare earth(III) salt catalyzed asymmetric Diels-Alder reaction of cyclopentadiene with a chiral dienophile in super-critical carbon dioxide (scCO(2)) proceeded rapidly to give the adduct with a higher diastereoselectivity than that in dichloromethane; optimization of the CO2 density increased the de value up to 77%.

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DOI： 10.1246/cl.2002.522

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DOI： 10.1246/cl.2002.522

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Language：Japanese   Publisher：中央大学  

CiNii Books

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Language：English   Publisher：GEORG THIEME VERLAG KG  

The addition of Grignard reagents to the ortho-amimo-formylferrocene (4) gave the corresponding amino alcohol (5a) of which the chiral center of the newly formed alcoholic carbon had the R configuration as the major diastereomer in 26-82% de, On the other hand, the stereochemical outcome was in contrast to the dialkylzinc addition to 7, the alcoholic carbon being the S configuration. The reduction of the chiral ortho-aminobenzoylferrocenes (7, 8) with DIBAH gave the corresponding amino alcohol (5a, 9a) with the R configuration of the alcoholic carbon as single diastereomers. while the reduction with LiAlH4 produced them with the S configuration of the alcoholic carbon as major diastereomers.

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The stereoselective reduction of alpha -keto esters/alpha -keto amides, which have various chiral auxiliaries using SmI2, is examined. 2(S)-Methoxymethylpyrrolidine, 1,1,2(S)- and 1,1,2(R)-triphenylethanediol were found to be suitable chiral auxiliaries that produced the corresponding alpha -hydroxy ester and amide in good diastereoselectivity with satisfactory yields. Allylation, the Reformatsky-type reaction, and the ketyl-alkene coupling reaction with the 1,1,2(R)-triphenylethanediol and 2(S)-methoxymethylpyrrolidine, derivative of the alpha -keto ester/amide proceeded smoothly with high diastereoselectivity. (C) 2001 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0040-4039(01)00676-1

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The stereoselective reduction of alpha -keto esters/alpha -keto amides, which have various chiral auxiliaries using SmI2, is examined. 2(S)-Methoxymethylpyrrolidine, 1,1,2(S)- and 1,1,2(R)-triphenylethanediol were found to be suitable chiral auxiliaries that produced the corresponding alpha -hydroxy ester and amide in good diastereoselectivity with satisfactory yields. Allylation, the Reformatsky-type reaction, and the ketyl-alkene coupling reaction with the 1,1,2(R)-triphenylethanediol and 2(S)-methoxymethylpyrrolidine, derivative of the alpha -keto ester/amide proceeded smoothly with high diastereoselectivity. (C) 2001 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0040-4039(01)00676-1

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Language：English   Publisher：GEORG THIEME VERLAG KG  

The chiral scandium (III) triflate/i-Pr-pybox complex efficiently catalyzes the asymmetric Diels-Alder reaction of 1,3-dienes with acyl-1,3-oxazolidin-2-ones (1a-c) afford the corresponding adducts in good yields with up to 90% ee. The reaction can be carried out in less toxic benzotrifluoride and supercritical carbon dioxide while remaining good selectivity (65-75% ee).

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Language：English   Publisher：WILEY-V C H VERLAG GMBH  

The chiral formylferrocenes 2-5 have been readily prepared in good yields by ortho-lithiation of the TMS-blocked or unblocked aminoferrocenes and subsequent reaction with DMF. The stereochemistry of the reaction of 2 with organometallic reagents has been examined. Reactions of 2 with Grignard and organolithium reagents gave the corresponding amino alcohol 6 in good yields with moderate to high diastereomeric excesses (up to 99%). When a dialkylzine was used as the nucleophile, a single diastereomer was obtained almost exclusively. This reaction may be rationalized in terms of an autocatalytic mechanism; the zinc alkoxide 7 generated in situ functions as an activator of dialkylzinc, which then adds to the formyl group. We have examined the asymmetric diethylzinc addition to benzaldehyde using formylferrocenes 2-5 or ferrocenyl amino alcohols 6a, 13 as catalysts, especially with regard to the relationship between catalytic activity and the chirality of the diastereomeric ferrocenes. Alkylation with 2, 3, and 6a gave (1R)-phenyl-1-propanol in good yields with high ee values (87-91% eel. On the other hand, reactions with 4, 5, and 13 gave the (S)-product in low yield and with low ee (38-57% eel. The low stereoselectivities can be attributed to stereochemical mismatching in the zinc alkoxides derived from 4 and 5. With aromatic, straight-chain, or branched aliphatic aldehydes, the stereoselective alkylation successfully gave the corresponding alcohols in good to high optical purities when 2 or 3 was employed as the catalyst. The optically active 1,2-ferrocenediol and -diphosphane have been prepared by means of the stereospecific substitution reaction with the amino alcohol 13 on treatment with acetic anhydride, followed by hydrolysis or substitution with diphenylphosphane.

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Language：English   Publisher：AMER CHEMICAL SOC  

The samarium(II) iodide mediated asymmetric Reformatsky-type reaction of chiral 3-bromoacetyl-2-oxazolidinones with various aldehydes was studied. A series of chiral 4-substituted 2-oxazolidinones 1-3 and 5,5-disubstituted "SuperQuat" oxazolidinones 4-5 were employed as chiral auxiliaries of the alpha-bromoacetic acid: The reaction of 1 with various aldehydes gave the alpha-unbranched beta-hydroxy carboximides in good yields with high diastereomeric excess values (up to >99% de). The majority of the reaction product derived from 5,5-diphenyl SuperQuat 5 were highly crystallinity; a single recrystallization yielding a diastereomerically pure product with the other diastereomer not detectable by spectroscopic methods.' The absolute configurations of the beta-hydroxy carboximides were determined by signs of optical rotations of the corresponding known ethyl esters referring to the literature values. Hydrolytic cleavage of the appended of beta-hydroxy moieties from the auxiliary SuperQuats was readily achieved under mild conditions using lithium hydroxide; the corresponding carboxylic acids and the returned SuperQuats were obtained in good yields without any evidence of racemization. The first step of the reaction is the reduction of the alpha-bromo group to produce the samarium enolate, which adds to an aldehyde. The absolute configuration of the adduct (7i) derive from benzaldehyde was found to be R, with the samarium enolate favoring the transition state predicted from chelation control of the reagent; this is in analogy to the discussion that has been used for the corresponding titanium enolate. The stereochemistry of the reaction may be explained by incorporating the Nerz-Stormes-Thornton chair transition structure model.

DOI： 10.1021/jo9914317

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Language：English   Publisher：AMER CHEMICAL SOC  

The samarium(II) iodide mediated asymmetric Reformatsky-type reaction of chiral 3-bromoacetyl-2-oxazolidinones with various aldehydes was studied. A series of chiral 4-substituted 2-oxazolidinones 1-3 and 5,5-disubstituted "SuperQuat" oxazolidinones 4-5 were employed as chiral auxiliaries of the alpha-bromoacetic acid: The reaction of 1 with various aldehydes gave the alpha-unbranched beta-hydroxy carboximides in good yields with high diastereomeric excess values (up to >99% de). The majority of the reaction product derived from 5,5-diphenyl SuperQuat 5 were highly crystallinity; a single recrystallization yielding a diastereomerically pure product with the other diastereomer not detectable by spectroscopic methods.' The absolute configurations of the beta-hydroxy carboximides were determined by signs of optical rotations of the corresponding known ethyl esters referring to the literature values. Hydrolytic cleavage of the appended of beta-hydroxy moieties from the auxiliary SuperQuats was readily achieved under mild conditions using lithium hydroxide; the corresponding carboxylic acids and the returned SuperQuats were obtained in good yields without any evidence of racemization. The first step of the reaction is the reduction of the alpha-bromo group to produce the samarium enolate, which adds to an aldehyde. The absolute configuration of the adduct (7i) derive from benzaldehyde was found to be R, with the samarium enolate favoring the transition state predicted from chelation control of the reagent; this is in analogy to the discussion that has been used for the corresponding titanium enolate. The stereochemistry of the reaction may be explained by incorporating the Nerz-Stormes-Thornton chair transition structure model.

DOI： 10.1021/jo9914317

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Language：English   Publisher：WILEY-LISS  

Preliminary investigations focused on the kinetic resolution of (+)-alpha-acetoxy mandelic carboxylic acid chloride with isopropyl SuperQuat and isopropyl Evans' homochiral auxiliaries. The addition of 2 equiv. of the acid chloride to the lithium salts of the auxiliaries (SuperQuat and Evans') at -100 degrees C in the THF afforded the corresponding N-acyl auxiliaries in high chemical yields (95% and 89%) and d.e.'s of 66% and 40%, respectively. Using the same mandelic acid chloride but incorporating SuperQuat aux iliaries derived from (S)-phenylglycine and (S)-phenylalanine yielded the corresponding N-acyl SuperQuats in 86% and 90% and d.e.'s of 66% and 30%, respectively. Substituting the phenyl group within the cr-acetoxy mandelic acid chloride for a n-butyl, tert-butyl and cyclohexyl group changed the d.e. significantly when kinetically resolved with isopropyl SuperQuat. The yields were all similar, i.e., similar to 90% but the d.e.'s varied considerably, with values of 20%, 50%, and 82%, respectively. Attempted kinetic resolution of alpha-methoxy-phenylacetyl chloride using the lithium salt of isopropyl SuperQuat revealed a diasteroselectivity of 45%, significantly lower than that obtained with the corresponding alpha-acetoxy carboxylic acid chlorides. (C) 2000 Wiley-Liss, Inc.

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CiNii Books

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Language：English   Publisher：CHEMICAL SOC JAPAN  

Addition of 1,4-butanediol diglycidyl ether (glycidyl = 2,3-epoxypropyl) to aqueous solutions of alpha-cyclodextrin (CD) leads to separation of the 2 : 1 complex from the solution. The C-13 CP/MAS NMR spectrum of the complex indicates the presence of diastereomeric oxirane groups formed via the complexation. 1,4-Butanediol diglycidyl ether forms the 1 : 1 or 2 : 2 complex with gamma-CD similarly from the aqueous reactions of the two compounds. 2,2-Dimethyltrimethylene glycol diglycidyl ether also forms water-insoluble host-guest complexes with (alpha-CD (2 : 1) and with gamma-CD (1 : 1 or 2 : 2). Poly(propylene glycol diglycidyl ether) with an M-n of 640 reacts with beta-CD to give the 1 : 4 complex. Poly(tetrahydrofuran) terminated with NH2 groups at both ends also forms the 1 :4 complexes both with alpha-CD and with gamma-CD.

DOI： 10.1246/bcsj.72.1541

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Addition of 1,4-butanediol diglycidyl ether (glycidyl = 2,3- epoxypropyl) to aqueous solutions of α-cyclodextrin (CD) leads to separation of the 2:1 complex from the solution. The 13C CP/MAS NMR spectrum of the complex indicates the presence of diastereomeric oxirane groups formed via the complexation. 1,4-Butanediol diglycidyl ether forms the 1:1 or 2:2 complex with γ-CD similarly from the aqueous reactions of the two compounds. 2,2-Dimethyltrimethylene glycol diglycidyl ether also forms water-insoluble host-guest complexes with α-CD (2:1) and with γ-CD (1:1 or 2:2). Poly(propylene glycol diglycidyl ether) with an M(n) of 640 reacts with β- CD to give the 1:4 complex. Poly(tetrahydrofuran) terminated with NH2 groups at both ends also forms the 1:4 complexes both with α-CD and with γ-CD.

DOI： 10.1246/bcsj.72.1541

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Chiral (ferrocenylseleno)methyl aryl and alkyl ketones (3) were easily prepared by the reaction of chiral ferrocenylselenenyl triflates and silyl enol ethers. They were reduced by DIBAH to give corresponding beta-hydroxy ferrocenyl selenides (4) in good yields with up to >99% de.

DOI： 10.1246/cl.1999.245

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Language：English   Publisher：Chemical Society of Japan  

Chiral (ferrocenylseleno)methyl aryl and alkyl ketones (3) were easily prepared by the reaction of the chiral ferrocenyl-selenenyl triflates and silyl enol ethers. They were reduced by DIBAH to give corresponding β-hydroxy ferrocenyl selenides (4) in good yields with up to &gt
99% de.

DOI： 10.1246/cl.1999.245

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Samarium(II) iodide mediated highly diastereoselective Reformatsky-type reaction of chiral alpha-bromoacetyl-2-oxazolidinones with aldehydes. (C) 1998 Elsevier Science Ltd. all rights reserved.

DOI： 10.1016/S0040-4039(98)01446-4

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Samarium(II) iodide mediated highly diastereoselective Reformatsky-type reaction of chiral alpha-bromoacetyl-2-oxazolidinones with aldehydes. (C) 1998 Elsevier Science Ltd. all rights reserved.

DOI： 10.1016/S0040-4039(98)01446-4

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Language：English   Publisher：GEORG THIEME VERLAG  

The chiral ferrocenecarbaldehyde bearing an amino group was used as a ligand of diethylzinc in the asymmetric alkylation of aldehydes. It effectively catalyzed the reaction with either aromatic, straight chain or branched aliphatic aldehydes to afford chiral alcohols in good yields with high enantiomeric excess (up to 93 % ee).

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Transesterification of N-acyloxazolidinones by treatment with an alcohol and lanthanum(III) iodide gives the corresponding esters in good to excellent yields under mild conditions with negligible racemization.

DOI： 10.1016/S0040-4039(98)00521-8

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Transesterification of N-acyloxazolidinones by treatment with an alcohol and lanthanum(III) iodide gives the corresponding esters in good to excellent yields under mild conditions with negligible racemization. (C) 1998 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0040-4039(98)00521-8

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Transesterification of N-acyloxazolidinones by treatment with an alcohol and lanthanum(III) iodide gives the corresponding esters in good to excellent yields under mild conditions with negligible racemization. (C) 1998 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0040-4039(98)00521-8

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Language：English   Publisher：Pergamon  

DOI： 10.1016/S0040-4039(98)00521-8

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Language：English   Publisher：米国化学会  

DOI： 10.1021/jo970982z

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Language：English   Publisher：AMER CHEMICAL SOC  

The Sc(OTf)(3)-catalyzed Friedel-Crafts alkylation reaction with an alcohol, an arenecarbaldehyde or an arenecarbaldehyde acetal as the alkylating agent affords a diarylmethane or an allylbenzene derivative highly selectively. The salient feature of this reaction is that only a catalytic amount of Sc(OTf)(3) can effect the reaction. Furthermore, Sc(OTf)(3) is recoverable and reusable after the synthetic reaction. The Sc(OTf)(3)-catalyzed benzylation using an arenecarbaldehyde and 1,3-propanediol or their acetal affords diarylmethane as a sole product in excellent yields in sharp contrast to the original Friedel-Crafts reaction. Since no reaction occurs in the absence of 1,3-propanediol, the reaction is considered to proceed through a redox process including a hydride shift. The hydride shift mechanism is strongly supported by the experimental evidence. The reaction of benzaldehyde with benzene in the presence of 1,3-propanediol-1,1,3,3,-d(4) gives rise to the deuterium incorporation into the benzylic carbon of diphenylmethane. Worthy of note is that 1,3-propanediol acts as the hydride source. Herein, diphenylmethyl 3-hydroxypropyl ether is assumed to be the most likely intermediate. In this reaction, Sc(OTf)(3) catalyst effectively promotes initial acetal formation, electrophilic aromatic substitution, and successive intramolecular hydride transfer.

DOI： 10.1021/jo970599u

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Asymmetric methoxyselenenylation of alkenes was studied using some chiral ferrocenylselenium compounds which were prepared from chiral ferrocenyl-substituted amine, sulfoxide, oxazoline, and pyrrolidine. The highest diastereoselectivity was observed using the chiral amino-substituted ferrocenylserenium triflates in the reaction with trans-beta-methylstyrene in an excellent yield. The reaction with silyl enol ethers gave chiral alpha-seleno ketone with moderate to excellent selectivities. The beta,gamma-unsaturated ester may be converted into the optically active gamma-alkoxy alpha,beta-unsaturated ester using ammonium persulfate in the presence of a catalytic amount of the chiral diferrocenyl diselenide in low optical yields.

DOI： 10.1021/jo970982z

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The dehydration of aldoximes with 2-methylene-1,3-dioxepane (MDO) proceeds smoothly in the presence of a catalytic amount of Lewis acid such as scandium(III) triflate to give corresponding nitriles in moderate to high yields under mild conditions. (C) 1997 Elsevier Science Ltd.

DOI： 10.1016/S0040-4039(97)01715-2

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The dehydration of aldoximes with 2-methylene-1,3-dioxepane (MDO) proceeds smoothly in the presence of a catalytic amount of Lewis acid such as scandium(III) triflate to give corresponding nitriles in moderate to high yields under mild conditions. (C) 1997 Elsevier Science Ltd.

DOI： 10.1016/S0040-4039(97)01715-2

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Language：English   Publisher：ROYAL SOC CHEMISTRY  

Optically active (R,S)- and (S,R)-tricarbonyl (2-[1-(N,N-dimethylamino)ethyl]benzenethiol) chromiums have been prepared in moderate yield by the regioselective lithiation of tricarbonyl [N,N-dimethyl-alpha(R)phenylethylamine]chromium and subsequent reaction of the product with elemental sulfur. The structure of the (R,S)-benzenethiolchromium complex was fully characterized by X-ray crystallography, The chiral benzenethiolchromium complexes reacted with cyclopentene oxide, cyclohexene oxide, 1-methylcyclohexene oxide, cycloheptene oxide and cyclooctene oxide and, after oxidative removal of the chromium moiety, gave the corresponding trans beta-hydroxyalkyl aryl sulfides in high yield with moderate diastereoselectivity, The reaction proceeded without additives and the diastereoselectivity was not affected by the addition of lanthanide(III) complexes which are known to promote the ring-opening of an epoxide with benzenethiol.

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DOI： 10.1021/jo970599u

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J-GLOBAL

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DOI： 10.1021/ja962965h

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DOI： 10.1021/ja962965h

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Reaction of 2-aryl-1,3-dioxane with arenes in the presence of a catalytic amount of trifluoromethanesulfonic acid gave the corresponding diarylmethanes in good to excellent yields. The acid-catalyzed Friedel-Crafts benzylation of arenes could altenatively be carried out using arenecarbaldehyde and 1,3-propanediol. The reaction was assumed to proceed through a redox process involving hydride shift from the cyclic acetal moiety to the benzylic carbon. The hydride shift was confirmed by the reaction with 5-ethyl-2-phenyl-4,4,6,6-tetradeuterio-1,3-dioxane, wherein more than 90% deuterium was incorporated into the benzylic carbon of the diphenylmethane. Diphenylmethyl ether Ph(2)CHOCH(2)CH(2)CH(2)OH also reacted with benzene to afford diphenylmethane under the same reaction conditions, suggesting that the ether should be the plausible intermediate that underwent the hydride shift.

DOI： 10.1021/jo961897e

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Reaction of 2-aryl-1,3-dioxane with arenes in the presence of a catalytic amount of trifluoromethanesulfonic acid gave the corresponding diarylmethanes in good to excellent yields. The acid-catalyzed Friedel-Crafts benzylation of arenes could altenatively be carried out using arenecarbaldehyde and 1,3-propanediol. The reaction was assumed to proceed through a redox process involving hydride shift from the cyclic acetal moiety to the benzylic carbon. The hydride shift was confirmed by the reaction with 5-ethyl-2-phenyl-4,4,6,6-tetradeuterio-1,3-dioxane, wherein more than 90% deuterium was incorporated into the benzylic carbon of the diphenylmethane. Diphenylmethyl ether Ph(2)CHOCH(2)CH(2)CH(2)OH also reacted with benzene to afford diphenylmethane under the same reaction conditions, suggesting that the ether should be the plausible intermediate that underwent the hydride shift.

DOI： 10.1021/jo961897e

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PubMed

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Scandium(III) trifluoromethanesulfonate catalyses the Friedel-Crafts benzylation of aromatic compounds with arenecarbaldehydes and propane-1,3-diol to produce, through a clean redox process, diarylmethanes in high to excellent yields.

DOI： 10.1039/cc9960002345

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Scandium(III) trifluoromethanesulfonate catalyses the Friedel-Crafts benzylation of aromatic compounds with arenecarbaldehydes and propane-1,3-diol to produce, through a clean redox process, diarylmethanes in high to excellent yields.

DOI： 10.1039/cc9960002345

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On treatment of a THF solution of Sm(OTf)(3) with 1 equiv of an organolithium or organomagnesium reagent-at ambient temperature, the purple or deep green solution of the divalent samarium triflate [Sm(OTf)(2)] was readily obtained. For this preparation, s-BuLi was the most effective as was evidenced by the reduction of a-phenylethyl iodide in the presence of HMPA. The Sm(OTf)(2) reagent mediated the Grignard-type reaction effectively in THF/HMPA; alkylation and allylation of ketones or aldehydes with alkyl, allyl, or benzyl halides proceeded via organosamarium intermediates. Diastereoselectivity of the samarium-Grignard reaction was examined using 2-methylcyclohexanone, 4-tert-butylcyclohexanone, and 2-phenylpropanal and was found to be higher in each case than that with SmI2. With 2-methylcyclohexanone, for example, Sm(OTf)(2) gave the greatest ratio of axial alcohol:equatorial alcohol = 99:1, and SmI2 gave a ratio of 91:9. Halides containing an ester or a silyl group were reactive in the Reformatsky- or Peterson-type reaction, respectively, using the Sm(OTf)(2) reagent.

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On treatment of a THF solution of Sm(OTf)(3) with 1 equiv of an organolithium or organomagnesium reagent-at ambient temperature, the purple or deep green solution of the divalent samarium triflate [Sm(OTf)(2)] was readily obtained. For this preparation, s-BuLi was the most effective as was evidenced by the reduction of a-phenylethyl iodide in the presence of HMPA. The Sm(OTf)(2) reagent mediated the Grignard-type reaction effectively in THF/HMPA; alkylation and allylation of ketones or aldehydes with alkyl, allyl, or benzyl halides proceeded via organosamarium intermediates. Diastereoselectivity of the samarium-Grignard reaction was examined using 2-methylcyclohexanone, 4-tert-butylcyclohexanone, and 2-phenylpropanal and was found to be higher in each case than that with SmI2. With 2-methylcyclohexanone, for example, Sm(OTf)(2) gave the greatest ratio of axial alcohol:equatorial alcohol = 99:1, and SmI2 gave a ratio of 91:9. Halides containing an ester or a silyl group were reactive in the Reformatsky- or Peterson-type reaction, respectively, using the Sm(OTf)(2) reagent.

DOI： 10.1021/jo960260s

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On treatment of a THF solution of Sm(OTf)(3) with 1 equiv of an organolithium or organomagnesium reagent-at ambient temperature, the purple or deep green solution of the divalent samarium triflate [Sm(OTf)(2)] was readily obtained. For this preparation, s-BuLi was the most effective as was evidenced by the reduction of a-phenylethyl iodide in the presence of HMPA. The Sm(OTf)(2) reagent mediated the Grignard-type reaction effectively in THF/HMPA; alkylation and allylation of ketones or aldehydes with alkyl, allyl, or benzyl halides proceeded via organosamarium intermediates. Diastereoselectivity of the samarium-Grignard reaction was examined using 2-methylcyclohexanone, 4-tert-butylcyclohexanone, and 2-phenylpropanal and was found to be higher in each case than that with SmI2. With 2-methylcyclohexanone, for example, Sm(OTf)(2) gave the greatest ratio of axial alcohol:equatorial alcohol = 99:1, and SmI2 gave a ratio of 91:9. Halides containing an ester or a silyl group were reactive in the Reformatsky- or Peterson-type reaction, respectively, using the Sm(OTf)(2) reagent.

DOI： 10.1021/jo960260s

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Language：English   Publisher：GEORG THIEME VERLAG  

Scandium(III) triflate [Sc(OTf)(3)] was found to be an Friedel-Crafts catalyst for benzylation and allylation reactions of various aromatics with the corresponding alcohols as the alkylating agents.

DOI： 10.1055/s-1996-5498

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Language：English   Publisher：GEORG THIEME VERLAG  

Scandium(III) triflate [Sc(OTf)(3)] was found to be an Friedel-Crafts catalyst for benzylation and allylation reactions of various aromatics with the corresponding alcohols as the alkylating agents.

DOI： 10.1055/s-1996-5498

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CiNii Books

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Transformation of a 3-halo ester to cyclopropanols has been accomplished in excellent yields under mild conditions employing a coupled reagent of samarium(II) diiodide with organometallic reagents. 5- and 6- Halo esters were also transformed into cyclopentanols and cyclohexanols, respectively, in low to moderate yields. The reaction with a 4-halo ester gave 2,2-disubstituted tetrahydrofuran as a major product that resulted from double alkylation followed by cyclization; a substituted cyclobutanol was formed in poor yield.

DOI： 10.1016/0040-4020(95)01039-4

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Transformation of a 3-halo ester to cyclopropanols has been accomplished in excellent yields under mild conditions employing a coupled reagent of samarium(II) diiodide with organometallic reagents. 5- and 6- Halo esters were also transformed into cyclopentanols and cyclohexanols, respectively, in low to moderate yields. The reaction with a 4-halo ester gave 2,2-disubstituted tetrahydrofuran as a major product that resulted from double alkylation followed by cyclization; a substituted cyclobutanol was formed in poor yield.

DOI： 10.1016/0040-4020(95)01039-4

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Language：English   Publisher：AMER CHEMICAL SOC  

As chiral ligands for transition metal complex-catalyzed asymmetric reactions, a variety of novel chiral ferrocenyl chalcogen compounds, which possess planar chirality due to the 1,2-unsymmetrically disubstituted ferrocene structure, have been prepared from chiral ferrocenes. There are seven diferrocenyl dichalcogenides (4-10), nine alkyl or aryl ferrocenyl chalcogenides (11-19), two bis(ferrocenylseleno)alkanes (20 and 21), two 1-(phenylchalcogeno)-1-[2-(diphenylphosphino)ferrocenyl]ethanes (22 and 24), and two 1-(phenylchalcogeno)-1-[1',2-bis(diphenylphosphino)ferrocenyl]ethanes (23 and 25). 2,3-O,O'-Isopropylidene-2,3-dihydroxy-1,4-bis(phenylchalcogeno)butanes (26-28) are also synthesized. The Rh(I) complex-catalyzed hydrosilylation of ketones with diphenylsilane in the presence of these chiral ligands including the reported [R,S;R,S]-bis[2-[1-(dimethylamino)ethyl]ferrocenyl]dichalcogenides (1-3), followed by hydrolysis with dilute HCl, affords the corresponding chiral alcohols (R-configuration) in moderate to quantitative yield with up to 88% enantiomeric excess (ee), Similar treatment of acetophenone in the presence of diferrocenyl dichalcogenides (1, 2, 3, and 10) and a catalytic amount of Ir(I) complex gives chiral 1-phenylethanol of the opposite configuration (S) compared with the Rh case in high yield with up to 23% ee. The new complex prepared from a cationic rhodium compound and the diferrocenyl diselenide (2) shows an activity for asymmetric hydrosilylation of acetophenone to afford 1-phenylethanol in 60% chemical yield with 60% ee. Asymmetric hydrosilylation of imines and asymmetric hydrogenation of an enamide also proceed smoothly using the Rh(I)-diselenide (2) catalytic system to give the corresponding sec-amines and amide with up to 53% and 69% ee, respectively. A catalytic cycle involving the formation of tetracoordinated rhodium(I)-dichalcogenide complex (two Se and two N atoms to one Rh) followed by oxidative addition of the Si-H bond to Rh(I) and carbonyl addition to the produced rhodium(III) hydride complex is proposed for hydrosilylation of ketones.

DOI： 10.1021/om950533u

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Language：English   Publisher：米国化学会  

DOI： 10.1021/om950533u

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Language：English   Publisher：AMER CHEMICAL SOC  

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Four novel optically active bis[(R,S)- and (S,R)-2-(1-dimethylaminoethyl)ferrocenyl] dichalcogenides [abbreviated as (R,S)- and (S,R)-(Fc*E), (E = S and Te)], each of which possesses two axial and two central elements of chirality, have been prepared by lithiation of commercially available chiral (1-dimethylaminoethyl)ferrocenes, followed by treatment with elemental sulfur or tellurium and air oxidation, in 42-65% isolated yields, The structure of the di-(S,R)-ferrocenyl disulfide has been fully characterized by X-ray crystallography. Ferrocenyl chalcogenide anions (Fc*E(-)) produced by reduction of the above (Fc*E)(2) and the known (Fc*Se)(2) with LiAlH4 in tetrahydrofuran are found to act as useful stereoselective nucleophiles for ring opening of meso-epoxides such as cyclohexene oxide, cyclopentene oxide, cyclooctene oxide and cis-stilbene oxide to give the corresponding ferrocenyl beta-hydroxyalkyl chalcogenides in high yields with up to 71% diastereoisomeric excess (de). Although the diastereoselectivity depends on the combination of chalcogen atom and meso-epoxide, it is generally higher with E = S and Se than with E = Te. Selenoxide elimination of (S,R)-2-(1-dimethylaminoethyl)ferrocenyl 2-hydroxycyclohexyl selenide (66% de), obtained by the ring opening of cyclohexene oxide with (S,R)-(Fc*Se)(2), gives (S)-cyclohex-2-enol with 60% ee. The S-configuration suggests that the ring opening, by the nucleophilic attack of the chiral ferrocenyl chalcogenide anion on the epoxide carbon, mainly occurs via the least hindered transition state considering the interactions between the epoxide, the 1-dimethylaminoethyl moiety and the ferrocene.

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Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：GEORG THIEME VERLAG  

Chiral acetal formation followed by cyanation of carbonyl compounds was successfully carried out in one-pot using chiral diols, scandium(III) triflate and then trimethylsilyl cyanide.

DOI： 10.1055/s-1995-5184

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Language：English   Publisher：英国化学会  

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Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：GEORG THIEME VERLAG  

Chiral acetal formation followed by cyanation of carbonyl compounds was successfully carried out in one-pot using chiral diols, scandium(III) triflate and then trimethylsilyl cyanide.

DOI： 10.1055/s-1995-5184

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DOI： 10.1016/0040-4039(95)01199-R

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Ring expansion reaction of a substituted cyclobutanone with CH2I2 and SmI2 proceeded cleanly in extended reaction time (15 h) to afford the corresponding cyclopentanone in good yield, whereas short reaction time (0.5 h) produced a mixture of iodohydrin and cyclopentanone.

DOI： 10.1016/0040-4039(95)01199-R

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Novel optically-active bis[2-[1-(dimethylamino)ethyl]ferrocenyl] diselenides ([R,S
R,S] and [S,R
S,R]), each of which possesses two axial and two central elements of chirality, have been prepared by lithiation of commercially available chiral [1-(dimethylamino)ethyl]ferrocenes, followed by reaction with elemental selenium and air oxidation, in 77–80% isolated yields. The structure of the [S,R
S,R]-bisferrocenyl diselenide has been fully characterized by X-ray crystallography. Six chiral ferrocenyl vinylic selenides and six chiral allylic ferrocenyl selenides have been newly prepared by reaction of the diselenides with the corresponding propiolate derivatives and allylic halides. The oxidation of the vinylic selenides with m-chloroperbenzoic acid in various organic solvents produces axially chiral allenecarboxylic esters via asymmetric selenoxide elimination in 27–59% chemical yields with high enantioselectivities (up to 89% ee). Similar treatment of the allylic selenides afforded the corresponding chiral allylic alcohols via asymmetric [2,3]sigmatropic rearrangement in 28–82% chemical yields with high enantioselectivities (up to 89% ee). The observed high enantioselectivities indicate that oxidation proceeds highly diastereoselectively, that the resultant chiral selenoxides are slow to racemize, and also that selenoxide elimination and [2,3]sigmatropic rearrangement proceed with little loss of optical activity. © 1995, American Chemical Society. All rights reserved.

DOI： 10.1021/jo00118a031

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Novel optically-active bis[2-[1-(dimethylamino)ethyl]ferrocenyl] diselenides ([R,S;R,S] and [S,R;S,R]), each of which possesses two axial and two central elements of chirality, have been prepared by lithiation of commercially available chiral [1-(dimethylamino)ethyl]ferrocenes, followed by reaction with elemental selenium and air oxidation, in 77-80% isolated yields. The structure of the [S,R;S,R]-bisferrocenyl diselenide has been fully characterized by X-ray crystallography. Six chiral ferrocenyl vinylic selenides and six chiral allylic ferrocenyl selenides have been newly prepared by reaction of the diselenides with the corresponding propiolate derivatives and allylic halides. The oxidation of the vinylic selenides with m-chloroperbenzoic acid in various organic solvents produces axially chiral allenecarboxylic esters via asymmetric selenoxide elimination in 27-59% chemical yields with high enantioselectivities (up to 89% ee). Similar treatment of the allylic selenides afforded the corresponding chiral allylic alcohols via asymmetric [2,3]sigmatropic rearrangement in 28-82% chemical yields with high enantioselectivities (up to 89% ee). The observed high enantioselectivities indicate that oxidation proceeds highly diastereoselectively, that the resultant chiral selenoxides are slow to racemize, and also that selenoxide elimination and [2,3]sigmatropic rearrangement proceed with little loss of optical activity.

DOI： 10.1021/jo00118a031

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CiNii Books

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Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

A chiral or a diastereomeric mixture of 1-[1-(N'N-dimethylaminoethyl)-2-(2'-hydroxyalkylseleno)]-ferrocene (DASF) was easily prepared by the chiral diferrocenyldiselenide (1)and:epoxides. DASF derivatives efficiently catalyzed the ethylation of aldehydes with diethyl zinc to give the secondary alcohols in good to excellent yield with up to 99 % ee.

DOI： 10.1016/0957-4166(95)00119-A

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A chiral or a diastereomeric mixture of 1-[1-N,N-dimethylaminoethyl)-2-(2′-hydroxyalkylseleno)]-ferrocene (DASF) was easily prepared by the chiral diferrocenyldiselenide (1) and epoxides. DASF derivatives efficiently catalyzed the ethylation of aldehydes with diethyl zinc to give the secondary alcohols in good to excellent yield with up to 99 % ee. © 1995.

DOI： 10.1016/0957-4166(95)00119-A

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Asymmetric intramolecular selenocyclisation of alkenoic acids, alkenols and olefinic urethanes using chiral ferrocenylselenenyl cations proceeds smoothly to give the corresponding lactones, cyclic ethers and nitrogen-heterocyclic compounds, respectively, in moderate yields with very high diastereoselectivities.

DOI： 10.1039/C39950002321

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Chiral diferrocenyl diselenide was easily converted into chiral ferrocenylselenyl bromide by treatment of bromine in CH2Cl2/CCl4 at -78 degrees C. This chiral electrophilic selenium reagent reacted with alkenes in the presence of methanol with high facial selectivity to afford selenomethoxylated adducts in moderate yields.

DOI： 10.1016/S0040-4039(00)78554-6

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Chiral diferrocenyl diselenide was easily converted into chiral ferrocenylselenyl bromide by treatment of bromine in CH2Cl2/CCl4 at -78 degrees C. This chiral electrophilic selenium reagent reacted with alkenes in the presence of methanol with high facial selectivity to afford selenomethoxylated adducts in moderate yields.

DOI： 10.1016/S0040-4039(00)78554-6

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Language：English   Publisher：日本化学会  

DOI： 10.1246/cl.1994.1981

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (other)   Publisher：近畿化学協会  

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Language：English   Publisher：CHEMICAL SOC JAPAN  

Samarium(II) triflate was readily prepared by the reaction of samarium(III) triflate with sec-butyllithium at room temperature in THF. Its reducing ability was examined by pinacol coupling of carbonyl compounds. Sm(OTf)(2) mediated Grignard-type reaction in THF-HMPA effectively; alkylation and allylation of ketones or aldehydes by simple alkyl, allyl, and benzyl halides proceeded via organosamarium intermediates.

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (other)   Publisher：日本化学会  

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The cross-aldol reaction between a ketone and an aldehyde proceeded smoothly with threo diastereoselection favorably mediated by ytterbium trifluoromethanesulfonate and tertiary amine in diethyl ether or in dichloromethane. A ytterbium enolate was trapped with chlorotrimethylsilane to afford a silyl enol ether.

DOI： 10.1246/bcsj.67.2227

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The cross-aldol reaction between a ketone and an aldehyde proceeded smoothly with threo diastereoselection favorably mediated by ytterbium trifluoromethanesulfonate and tertiary amine in diethyl ether or in dichloromethane. A ytterbium enolate was trapped with chlorotrimethylsilane to afford a silyl enol ether.

DOI： 10.1246/bcsj.67.2227

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (other)   Publisher：近畿化学協会  

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The new chiral compounds, (R,S)-di[2-(1-dimethylaminoethyl)ferrocenyl] dichalcogenides (R,S)-{[EC(5)H(3)CHMe(NMe(2))]Fe(C5H5)}, (E = S, Se, Te), work effectively as chiral ligands for the rhodium(i)-catalysed asymmetric hydrosilylation of alkyl aryl ketones resulting in high enantiomeric excess and moderate chemical yields.

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Two optically active diferrocenyl diselenides, each of which possesses two chiral centers, were newly prepared from commercial 1-(dimethylamino)ethylferrocenes and applied to induce highly enantioselective selenoxide elimination producing axially chiral allenecarboxylic esters. © 1994.

DOI： 10.1016/S0040-4039(00)76844-4

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Two optically active diferrocenyl diselenides, each of which possesses two chiral centers, were newly prepared from commercial 1-(dimethylamino)ethylferrocenes and applied to induce highly enantioselective selenoxide elimination producing axially chiral allenecarboxylic esters.

DOI： 10.1016/S0040-4039(00)76844-4

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The new chiral compounds, (R,S)-di[2-(1-dimethylaminoethyl)ferrocenyl] dichalcogenides (R,S)-{[EC5H3CHMe(NMe2)] Fe(C5H5)}2 (E=S, Se, Te), work effectively as chiral ligands for the rhodium(I)-catalysed asymmetric hydrosilylation of alkyl aryl ketones resulting in high enantiomeric excess and moderate chemical yields.

DOI： 10.1039/C39940001375

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Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：GEORG THIEME VERLAG  

Treatment of a mixture of a haloacetal (1) and tert-butanol with 2.5 equiv of samarium (II) diiodide in THF-HMPA gave in good conversion the cyclic acetal (2), which was transformed to the gamma-lactone (3) with Jones oxidation (overall yield, 70-90 %). The stereochemistry of the 2,4- (2;R1=H, R2=Me, Et) or 2,3-disubustituted lactones were predominantly trans (trans: cis=86:14-98:2).

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Samarium diiodide promoted reductive coupling between ethyl 2-(bromomethyl)acrylate (1) and carbonyl compounds (2) was studied. The 2-ethoxycarbonyl allylation with benzaldehyde, hexanal, acetophenane, and benzophenone proceeded in tetrahydrofuran-hexamethyl-phosphoric triamide at -78-degrees-C to room temperature, and the corresponding alpha-methylene-gamma-butyrolactones (3) were produced in moderate yields. However, the reaction with cyclohexanone and diethyl ketone only resulted in a reductive dimerization of 1 ; no desired 3 were obtained and diethyl 2, 5-bis(methylene)hexanedioate was produced in 50-70% yields. When the reaction was carried out by using ethyl 2-(acetoxymethyl)acrylate 7 instead of 1 as a precursor in the presence of catalytic amount of tetrakis(triphenylphosphine)palladium complex, the corresponding 3 were obtained from the reaction not only with benzaldehyde, hexanal, and acetophenone but also cyclohexanone which did not give 3 in the reaction with 1.

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Tetraallyllanthanoid ate complex (1), which was readily prepared in situ from tetraallyltin, lanthanoid trichloride, and butyllithium in tetrahydrofuran (THF), reacts smoothly with alpha-enones (3-11) with a high degree of 1,2-regioselectivity (1,2: 1,4=>99: 1) to give 1,5-diene-3-ols in good to excellent yields. The mechanistic study with 4,4-(ethylenedioxy)-2,6-dimethyl-2,5-cyclohexadienone (29) as a probe suggests that single electron transfer (SET) may be involved in this carbonyl allylation reaction with 1. Allylative ring opening of styrene oxide with 1 occurs at the more subsituted carbon (alpha-attack) in higher selectivity (alpha: beta=85: 15) than with allyllithium and allylmagnesium bromide in diethyl ether. The complex 1 reacts with 3,4-epoxy-1-butene (35) in diethyl ether predominantly at the most substituted carbon of the oxirane to give 3-hydroxymethyl-1,5-hexadiene (36) together with 1,6-heptadien-3-ol (37), (E) and (Z)-2,6-heptadienols (38) (36: 37:38=87: 9:4)

DOI： 10.1246/bcsj.65.3308

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Language：English   Publisher：CHEMICAL SOC JAPAN  

Tetraallyllanthanoid ate complex (1), which was readily prepared in situ from tetraallyltin, lanthanoid trichloride, and butyllithium in tetrahydrofuran (THF), reacts smoothly with alpha-enones (3-11) with a high degree of 1,2-regioselectivity (1,2: 1,4=>99: 1) to give 1,5-diene-3-ols in good to excellent yields. The mechanistic study with 4,4-(ethylenedioxy)-2,6-dimethyl-2,5-cyclohexadienone (29) as a probe suggests that single electron transfer (SET) may be involved in this carbonyl allylation reaction with 1. Allylative ring opening of styrene oxide with 1 occurs at the more subsituted carbon (alpha-attack) in higher selectivity (alpha: beta=85: 15) than with allyllithium and allylmagnesium bromide in diethyl ether. The complex 1 reacts with 3,4-epoxy-1-butene (35) in diethyl ether predominantly at the most substituted carbon of the oxirane to give 3-hydroxymethyl-1,5-hexadiene (36) together with 1,6-heptadien-3-ol (37), (E) and (Z)-2,6-heptadienols (38) (36: 37:38=87: 9:4)

DOI： 10.1246/bcsj.65.3308

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Language：English   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Transformation of alpha,beta-halo ester to the cyclopropanols by a coupled reagent of samarium(II) diiodide with Grignard reagent in tetrahydrofuran-hexamethylphosphoric triamide was very successfully under mild conditions.

DOI： 10.1016/0040-4039(91)80567-P

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Language：English   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Transformation of alpha,beta-halo ester to the cyclopropanols by a coupled reagent of samarium(II) diiodide with Grignard reagent in tetrahydrofuran-hexamethylphosphoric triamide was very successfully under mild conditions.

DOI： 10.1016/0040-4039(91)80567-P

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Language：English   Publisher：IUPAC  

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Language：English   Publisher：AMER CHEMICAL SOC  

DOI： 10.1021/om00162a019

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Language：English   Publisher：ROYAL SOC CHEMISTRY  

DOI： 10.1039/c39900000939

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Language：English   Publisher：ROYAL SOC CHEMISTRY  

DOI： 10.1039/c39900000939

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Language：English   Publisher：日本化学会  

DOI： 10.1246/cl.1990.173

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Language：English   Publisher：日本化学会  

Anionic conductivity of poly(vinyl chloride)-tetrabutylammonium iodide composite film has been remarkably increased by the addition of organotin compounds. At a high content of tributyltin iodide, the conductivity has been enhanced up to the order of 10^−4 S/cm at 25 °C.

DOI： 10.1246/cl.1990.127

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Language：English   Publisher：日本化学会  

DOI： 10.1246/cl.1990.927

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Language：English   Publisher：Elsevier  

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Language：English   Publisher：日本化学会  

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Language：English   Publisher：AMER CHEMICAL SOC  

DOI： 10.1021/jo00292a043

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Language：English   Publisher：AMER CHEMICAL SOC  

DOI： 10.1021/jo00292a043

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Language：English   Publisher：CHEMICAL SOC JAPAN  

DOI： 10.1246/cl.1990.173

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DOI： 10.1002/hc.520010611

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Language：English  

Diphenyl diselenide and diphenyl ditelluride were reduced by samarium (II) diiodide in tetrahydrofuran‐hexamethylphosphoric triamide to produce samarium phenylselenolate and samarium phenyltellurolate, respectively. This new selenolate or tellurolate anion species reacted smoothly with alkyl, allyl, and benzyl halides to give alkyl‐, allyl‐, and benzylphenyl selenides or tellurides in good yields under mild and neutral conditions. The samarium selenolate reacted with α‐halo ketones to give the corresponding α‐phenylseleno ketones. 1,4‐Addition with α,β‐enones proceeded to give 3‐phenylseleno ketones in moderate yields. Isolation of phenylselenotributyltin or phenylseleno‐trimethylsilane by transmetalation with tributyltin iodide or trimethylchlorosilane, respectively, suggested the presence of the samarium selenolate species. Copyright © 1990 VCH Publishers, Inc.

DOI： 10.1002/hc.520010611

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Language：English   Publisher：JOHN WILEY & SONS LTD  

DOI： 10.1002/aoc.590040107

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Language：English   Publisher：CHEMICAL SOC JAPAN  

DOI： 10.1246/bcsj.62.2348

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Language：English   Publisher：CHEMICAL SOC JAPAN  

DOI： 10.1246/bcsj.62.2348

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Language：English   Publisher：ISF-JOCS(日本油化学会）  

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Language：English   Publisher：ROYAL SOC CHEMISTRY  

DOI： 10.1039/p19880001669

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Language：English   Publisher：ROYAL SOC CHEMISTRY  

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Language：English   Publisher：英国化学会  

DOI： 10.1039/p19880001669

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Language：English   Publisher：ROYAL SOC CHEMISTRY  

DOI： 10.1039/a901355e

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Language：English   Publisher：IUPAC-(国際純正と応用化学連合）  

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Language：English   Publisher：ROYAL SOC CHEMISTRY  

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DOI： 10.1039/c39870000919

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DOI： 10.1039/c39870000920

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Language：English   Publisher：ROYAL SOC CHEMISTRY  

DOI： 10.1039/c39870000920

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Language：English   Publisher：英国化学会  

DOI： 10.1039/a901355e

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Language：English   Publisher：ELSEVIER SCIENCE SA  

DOI： 10.1016/0022-328X(86)82076-9

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Language：English   Publisher：ROYAL SOC CHEMISTRY  

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Language：English   Publisher：ROYAL SOC CHEMISTRY  

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Language：English   Publisher：ELSEVIER SCIENCE SA  

DOI： 10.1016/0022-328X(86)82076-9

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Language：English   Publisher：ROYAL SOC CHEMISTRY  

DOI： 10.1039/c39860000624

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Language：English   Publisher：近畿化学協会  

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Language：English   Publisher：ROYAL SOC CHEMISTRY  

DOI： 10.1039/c39860000624

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Language：English   Publisher：ROYAL SOC CHEMISTRY  

DOI： 10.1039/c39860000475

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DOI： 10.1039/c39860000475

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Language：English   Publisher：ELSEVIER SCIENCE SA LAUSANNE  

DOI： 10.1016/0022-328X(86)82013-7

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Language：English   Publisher：ELSEVIER SCIENCE SA LAUSANNE  

DOI： 10.1016/0022-328X(86)82013-7

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Language：English   Publisher：英国化学会  

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Language：English   Publisher：Pergamon Press  

DOI： 10.1016/S0040-4039(00)61958-5

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Language：English   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

DOI： 10.1016/S0040-4039(00)61958-5

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Language：English   Publisher：ROYAL SOC CHEMISTRY  

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Language：English   Publisher：CHEMICAL SOC JAPAN  

DOI： 10.1246/cl.1985.199

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Language：English   Publisher：ROYAL SOC CHEMISTRY  

DOI： 10.1039/c39850000777

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Language：English   Publisher：ROYAL SOC CHEMISTRY  

DOI： 10.1039/c39850000777

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Language：English   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

DOI： 10.1016/S0040-4039(00)61965-2

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Language：English   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

DOI： 10.1016/S0040-4039(00)61965-2

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Language：English   Publisher：ROYAL SOC CHEMISTRY  

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Language：English   Publisher：ROYAL SOC CHEMISTRY  

DOI： 10.1039/c39840000426

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Language：English   Publisher：ELSEVIER SCIENCE SA LAUSANNE  

DOI： 10.1016/0022-328X(84)80257-0

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Language：English   Publisher：ELSEVIER SCIENCE SA LAUSANNE  

DOI： 10.1016/0022-328X(84)80257-0

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Language：English   Publisher：ROYAL SOC CHEMISTRY  

DOI： 10.1039/c39840000426

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Language：English   Publisher：AMER CHEMICAL SOC  

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Language：English   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

DOI： 10.1016/S0040-4039(00)88338-0

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Language：English   Publisher：ELSEVIER SCIENCE SA LAUSANNE  

DOI： 10.1016/0022-328X(83)85051-7

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