Chiral bis(oxazolinylphenyl)amines proved to be efficient auxiliary ligands for iron and cobalt catalysts with high activity for asymmetrichydrosilylation of ketones and asymmetric conjugate hydrosilylation of enones.
complexes. Subsequent treatment of the resulting silver compound with [IrCl(cod)]2 yielded monodentate IrCl(cod)(NHC), which was stable in air. The NHC–Ir complex facilitated efficient asymmetric hydrosilylation of ketones using (EtO)2MeSiH under ambient conditions. A chiral ligand containing an isobutyl stereodirecting group was found to be the best ligand for the functionalized NHC–Ir complexes that were
Chiral Frustrated Lewis Pairs Catalyzed Highly Enantioselective Hydrosilylations of Ketones
作者:Xiaoqin Liu、Qiaotian Wang、Caifang Han、Xiangqing Feng、Haifeng Du
DOI:10.1002/cjoc.201900121
日期:2019.7
A highlyenantioselective Piers‐type hydrosilylation of simple ketones was successfully realized using a chiral frustrated Lewis pair of tri‐tert‐butylphosphine and chiral diene‐derived borane as catalyst. A wide range of optically active secondary alcohols were furnished in 80%—99% yields with 81%—97% ee's under mild reaction conditions.
Asymmetric catalysis with readily available, cheap, and non-toxic alkaline earth metal catalysts represents a sustainable alternative to conventional synthesis methodologies. In this context, we describe the development of a first MgII -catalyzed enantioselective hydroboration providing the products with excellent yields and enantioselectivities. NMR spectroscopy studies and DFT calculations provide
Studies on Rhizopus arrhizus mediated enantioselective reduction of arylalkanones
作者:Neeta A Salvi、Subrata Chattopadhyay
DOI:10.1016/s0040-4020(01)00134-x
日期:2001.4
The effect of substitution on the biotransformation of various arylalkanones using Rhizopus arrhizus was investigated. The organism was found to be promising for the reduction of phenylalkanones and arylethanones with good to excellent enantioselectivity. The reduction followed Prelog's rule giving the (S)-carbinols in all the cases. The enantioselectivity of the reaction improved with increasing size