路易斯碱催化的不对称C-酰化反应

Lewis base catalyzed asymmetric C-acylation

不对称C-酰化反应是便捷构建季碳手性中心最有效的方法之一.不对称C-酰化反应可分为间接不对称C-酰化与直接不对称C-酰化.路易斯碱催化剂在这类反应中起到了关键性作用.作用于C-酰化反应的路易斯碱催化剂可分为叔胺类、叔膦类和亲核氧类.其中叔胺类应用最广泛并且结构最多样,主要包括氨基吡啶、脒和咪唑三类结构.本文梳理了近年来路易斯碱催化不对称C-酰化反应的发展历程,尤其详细介绍了手性双环咪唑催化的直接不对称C-酰化反应,着重探讨了催化剂在这些反应中的催化性能和作用机理.

Asymmetric C-acylation is one of the most useful methods for the convenient construction of quaternary stereocenters.Asymmetric C-acylation can be divided into indirect C-acylation and direct C-acylation.Lewis base catalysts play key roles in this type of reactions.These catalysts can be divided into tertiary amines,tertiary phosphines and the catalysts bearing an oxygen nucleophilic site.Among them,tertiary amines,including aminopyridines,amidines and imidazoles,are most widely used due to its structural diversity and stability.This review outlines the development of the asymmetric C-acylation catalyzed by Lewis base especially the direct C-acylation catalyzed by chiral bicyclic imidazoles,and focuses on the performance and mechanism of the catalysts in these reactions.