手性胺/金(Ⅰ)协同催化的不对称串联反应研究

Asymmetric Tandem Reactions Achieved by Chiral Amine & Gold(Ⅰ) Cooperative Catalysis

协同催化是改善反应效率和选择性控制的一种有力策略.通过组合不同催化剂来获得协同效应,实现单一催化剂难以企及的高反应活性和选择性以及发展挑战性新反应,是不对称催化的重要研究内容.手性胺根据胺结构的不同,可通过烯胺、亚胺或攫氢活化等方式来活化具有α-氢的醛(酮)、共轭烯醛(酮)、活泼次甲基或亚甲基化合物;而阳离子型的一价金催化可以高效活化烯烃、炔烃和重氮化合物,因此,结合两种催化剂的特点来发展不对称串联反应,实现从简单原料出发构建较复杂手性化合物受到关注.本综述旨在介绍手性伯胺、仲胺或叔胺与一价金协同催化来实现的不对称串联反应,重点关注两者协同催化的优势、避免催化剂失活的方法以及讨论未来的发展空间,进而为从事不对称催化相关的研究人员提供一些有益参考和借鉴.

Cooperative catalysis is a powerful strategy to improve the efficiency and selectivity of organic reactions. It is of current interest in asymmetric catalysis to combine different catalysts to secure synergistic effects to realize high reaction activity and selectivity unattainable by a single catalyst, and to develop challenging new reactions. Depending on their structures,chiral amines can activate aldehydes or ketones with α-protons, conjugated enals or enones, activated methine or methylene compounds via enamine catalysis, iminium catalysis or deprotonative activation. On the other hand, cationic gold(Ⅰ) catalysis can efficiently activate olefins, alkynes or diazo compounds for functionalization reactions. Therefore, it has attracted ever-increasing attention to combine the reactivity patterns of the two types of catalysts to develop asymmetric tandem reactions,and paves a facile way to construct complex chiral compounds from simple starting materials. The purpose of this review is to introduce the asymmetric tandem reactions achieved by chiral amine & gold(Ⅰ) catalysis, focusing on the advantages of such type of cooperative catalysis, the way to avoid catalyst deactivation, as well as its future development, so as to provide some useful references for researchers engaged in asymmetric catalysis.