Chiral aldehyde catalysis: a highly promising concept in asymmetric catalysis

• 来源期刊: 中国科学:化学（英文版）
• 年，卷（期）: 2019,（1）
• 页码范围: 3-4
• 页数: 2页
• 语种: 英文

摘要

Asymmetric organocatalysis has been a robust tool for manufacturing optically active molecules,in addition to asymmetric metal and biocatalysis [1].The development of new concepts and catalysts to enable the creation of efficient synthetic methods has been a longstanding activity in this field.During the last decades,a diverse spectrum of chiral organocatalysts,including ketones,amine,Brφnsted acids and bases,phase-transfer catalysts,and nucleophilic catalysts,have been developed,culminating in a large number of transformations enabling the efficient construction of optically active natural and unnatural compounds.Despite of these great achievements,the asymmetric direct α-functionalization of N-unprotected amines,which offers a very straightforward approach to access chiral amine compounds,is very hard to be realized by virtue of commonly available organocatalytic concepts.It is well known that the α-C-H bond of an amine can be activated by an aldehyde via the formation of an imine.Importantly,the imine formation is basically reversible to thereby allow chiral aldehydes to be promising organocatalysts for the direct α-functionalization of N-unprotected amines.Nature has already pointed out this possibility [2],however,the mimic of nature to design artificial chiral aldehyde catalysts and asymmetric processes has not gained breakthroughs,until recently [3,4].