National Engineering Research Center of Chiral Drugs, Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China.
Org Lett. 2011 Oct 7;13(19):5064-7. doi: 10.1021/ol201927c. Epub 2011 Aug 31.
A simple catalyst system assembled from an enantiomerically pure diamine ligand and Ni(OAc)(2) efficiently generates chiral metal enolates derived from 3-substituted oxindoles bearing an N-1 carbonyl group. The enolates smoothly undergo diastereo- and enantioselective conjugate addition to a wide range of nitroolefins under mild reaction conditions, furnishing 3,3-disubstituted oxindole products bearing two vicinal quaternary/tertiary stereocenters in 74-95% yields and 60:40 to 99:1 dr, 71-97% ee.
一个由手性纯二胺配体和 Ni(OAc)2 组成的简单催化剂体系能够有效地生成来自于具有 N-1 羰基的 3-取代的氧化吲哚的手性金属烯醇盐。在温和的反应条件下，烯醇盐能够顺利地进行对广泛的硝基烯烃的非对映选择性和对映选择性共轭加成，以 74-95%的收率和 60:40 至 99:1 的 dr，71-97%的 ee 得到了带有两个相邻的季碳/叔碳立体中心的 3,3-二取代的氧化吲哚产物。
