Synthesis of rhodium(I) and iridium(I) complexes of chiral N-heterocyclic carbenes and their application to asymmetric transfer hydrogenation
作者:Gavin Dyson、Jean-Cédric Frison、Adrian C. Whitwood、Richard E. Douthwaite
DOI:10.1039/b909290k
日期:——
and iridium complexes of chiral NHC–phenolimine and NHC–amine ligands have been prepared and studied for asymmetric transfer hydrogenation. X-ray and NMR spectroscopy show that for NHC–phenolimine complexes abstraction of chloride results in a change in ligand coordination from NHC only to chelating NHC–imine. Complexes of NHC–amines are inactive for transfer hydrogenation, whereas complexes of NHC–phenolimines
New C2-symmetric tetrafluorobenzobarreleneligands were prepared and applied successfully to the rhodium-catalyzedasymmetric addition of arylboronic acids to aromatic aldehydes giving chiral diarylmethanols in high yield with high enantioselectivity.
Catalytic enantioselective arylation of aldehydes: boronic acids as a suitable source of transferable aryl groups
作者:Antonio L. Braga、Diogo S. Lüdtke、Fabrício Vargas、Marcio W. Paixão
DOI:10.1039/b501485a
日期:——
The catalytic enantioselective arylation of several aldehydes using boronic acids as the source of transferable aryl groups is described; the reaction is found to proceed in excellent yields and high enantioselectivities (up to 97% ee) in the presence of a chiral amino alcohol.
An Efficient Diphosphine/Hybrid-Amine Combination for Ruthenium(II)-Catalyzed Asymmetric Hydrogenation of Aryl Ketones
作者:Yuehui Li、Yougui Zhou、Qixun Shi、Kuiling Ding、Ryoji Noyori、Christian A. Sandoval
DOI:10.1002/adsc.201000577
日期:2011.2.11
1H-benzimidazole-2-methanamine (BIMA) ligands in combination with 2,3-O-isopropylidene-2,3-dihydroxy-1,4-bis(diphenylphosphino)butane (DIOP) afford efficient catalytic systems for the ruthenium(II)-catalyzed asymmetrichydrogenation (AH) of a number of aryl ketones. The AH proceeds smoothly with substrate-to-catalyst (S/C) molar ratios of up to 100,000 (TOF of 6500 h−1, 8 atm) giving chiral alcohols in up
现成的基于模块化胺/苯并咪唑的1 H-苯并咪唑-2-甲胺(BIMA)配体与2,3- O-异亚丙基-2,3-二羟基-1,4-双(二苯基膦基)丁烷(DIOP)组合)为钌(II)催化的许多芳基酮的不对称氢化(AH)提供了有效的催化体系。AH顺利进行,底物与催化剂(S / C)的摩尔比最高为100,000(TOF为6500 h -1,8 atm),手性醇含量高达99%ee。
Novel Ruthenium Complexes Having Hybrid Amine Ligands, Their Preparation And Use
申请人:Sandoval Christian A.
公开号:US20110092712A1
公开(公告)日:2011-04-21
The invention relates to a novel class of ruthenium complexes containing phosphine and hybrid amine ligands, their preparation and use as catalysts in the reduction of simple ketones to alcohols by molecular hydrogenation. The reactivity and enantioselectivity of such complexes in the asymmetric hydrogenation of simple ketones could be enchanced by the addition of some selective additives.