Enantioselective, Organocatalytic Reduction of Ketones using Bifunctional Thiourea-Amine Catalysts
摘要:
Prochiral ketones are reduced to enantioenriched, secondary alcohols using catecholborane and a family of air-stable, bifunctional thiourea amine organocatalysts. Asymmetric induction is proposed to arise from the in situ complexation between the borane and chiral thiourea amine organocatalyst resulting in a stereochemically biased boronate amine complex. The hydride in the complex is endowed with enhanced nucleophilicity while the thiourea concomitantly embraces and activates the carbonyl.
Chiral thiourea compounds and process for enantioselective reduction of ketones
申请人:Li Derun
公开号:US20090253919A1
公开(公告)日:2009-10-08
Chiral thioureas are effective catalysts for the borane reduction of prochiral ketones to optically active alcohols. A prochiral ketone may be reduced to an optically active alcohol in the presence of a substantially sub-stoichiometric amount of chiral thiourea. The asymmetric thiourea compound of the present invention may be produced according to a production method described herein.
Discovery of Bifunctional Thiourea/Secondary-Amine Organocatalysts for the Highly Stereoselective Nitro-Mannich Reaction of α-Substituted Nitroacetates
Enantioselective, Organocatalytic Reduction of Ketones using Bifunctional Thiourea-Amine Catalysts
作者:De Run Li、Anyu He、J. R. Falck
DOI:10.1021/ol100365c
日期:2010.4.16
Prochiral ketones are reduced to enantioenriched, secondary alcohols using catecholborane and a family of air-stable, bifunctional thiourea amine organocatalysts. Asymmetric induction is proposed to arise from the in situ complexation between the borane and chiral thiourea amine organocatalyst resulting in a stereochemically biased boronate amine complex. The hydride in the complex is endowed with enhanced nucleophilicity while the thiourea concomitantly embraces and activates the carbonyl.