Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China.
J Org Chem. 2011 May 20;76(10):4008-17. doi: 10.1021/jo2004378. Epub 2011 Apr 18.
An organocatalytic asymmetric Michael addition reaction of 3-substituted oxindoles to protected 2-amino-1-nitroethenes has been developed. The reaction is catalyzed by a simple and readily available amino-indanol derivative and affords the desired products in very high yields (up to 99%) with excellent diastereoselectivities (up to >99:1) and very good enantioselectivities (up to 90%). Significantly, this study provides a general catalytic method for the construction of 3,3'-disubstituted oxindoles bearing α,β-diamino functionality as well as vicinal chiral quaternary/tertiary stereocenters. The potential utility of the protocol also had been demonstrated by gram-scale reaction and the versatile conversion of product. Furthermore, On the basis of the comprehensive experimental results and the absolute configuration of one of the Michael adducts, a work model was also proposed to explain the origin of asymmetric induction.
已开发出一种手性有机催化的 3-取代氧吲哚与保护的 2-氨基-1-硝基乙烯的不对称迈克尔加成反应。该反应由简单易得的氨基-2-茚醇衍生物催化，以非常高的收率（高达 99%）、极好的非对映选择性（高达>99:1）和非常好的对映选择性（高达 90%）得到所需产物。值得注意的是，该研究为构建具有α,β-二氨基官能团以及毗邻手性季碳/叔碳中心的 3,3'-二取代氧吲哚提供了一种通用的催化方法。该方案的潜在用途也通过克级反应和产物的多功能转化得到了证明。此外，基于全面的实验结果和其中一个迈克尔加成物的绝对构型，还提出了一个工作模型来解释不对称诱导的起源。
