Enantioselective Conjugate Silyl Additions to α,β-Unsaturated Aldehydes Catalyzed by Combination of Transition Metal and Chiral Amine Catalysts
作者:Ismail Ibrahem、Stefano Santoro、Fahmi Himo、Armando Córdova
DOI:10.1002/adsc.201000908
日期:2011.2.11
We report that transition metal-catalyzed nucleophilic activation can be combined with chiral amine-catalyzed iminium activation as exemplified by the unprecedented enantioselective conjugate addition of a dimethylsilanyl group to α,β-unsaturated aldehydes. These reactions proceed with excellent 1,4-selectivity to afford the corresponding β-silyl aldehyde products 3 in high yields and up to 97:3 er
我们报道过渡金属催化的亲核活化可以与手性胺催化的亚胺基活化结合在一起,这是通过对α,β-不饱和醛的二甲基甲硅烷基空前的对映选择性共轭加成来证明的。这些反应以优异的1,4-选择性进行,使用廉价的台式稳定的铜盐和简单的手性胺催化剂,可以高产率和高达97:3的速率得到相应的β-甲硅烷基醛产物3 。该反应还可以产生具有良好对映选择性的四元立体中心。进行密度函数计算以阐明反应机理和对映选择性的起源。