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.
Highly Enantioselective Cobalt-Catalyzed Hydroboration of Diaryl Ketones
作者:Wenbo Liu、Jun Guo、Shipei Xing、Zhan Lu
DOI:10.1021/acs.orglett.0c00293
日期:2020.4.3
A highlyenantioselective cobalt-catalyzed hydroboration of diaryl ketones with pinacolborane was developed using chiral imidazole iminopyridine as a ligand to access chiral benzhydrols in good to excellent yields and ee. This protocol could be carried out in a gram scale under mild reaction conditions with good functional group tolerance. Chiral biologically active 3-substituted phthalide and (S)-neobenodine
Asymmetric hydrosilylation of ketones catalyzed by complexes formed from trans-diaminocyclohexane-based diamines and diethylzinc
作者:Jadwiga Gajewy、Jacek Gawronski、Marcin Kwit
DOI:10.1007/s00706-012-0754-0
日期:2012.7
Chiral acyclic and macrocyclic amines derived from trans-1,2-diaminocyclohexane in complexes with diethylzinc efficiently catalyze asymmetric hydrosilylation of aryl-alkyl and aryl-aryl ketones with enantiomeric excess of the product up to 86 %. A trianglamine ligand with a cyclic structure or the presence of an additional coordinating group increases the enantioselectivity of the reaction, in comparison