Organocatalytic Asymmetric Synthesis of 3-Chlorooxindoles Bearing Adjacent Quaternary–Tertiary Centers
作者:Artur Noole、Ivar Järving、Franz Werner、Margus Lopp、Andrei Malkov、Tõnis Kanger
DOI:10.1021/ol302245b
日期:2012.9.21
A new methodology was developed for the synthesis of enantiomerically enriched 3,3-disubstituted 3-chlorooxindoles 3 via a Michael addition of 3-chloroxindoles to nitroolefins 2, catalyzed by chiral squaramide 10. Products with adjacent quaternary–tertiary centers were isolated in excellent yields (up to 99%), high diastereoselectivities (up to 11:1), and enantiomeric purities (up to 92%). This is
一种新方法被用于对映体富集3,3-二取代的3- chlorooxindoles的合成开发3经由迈克尔加成3- chloroxindoles到nitroolefins 2,通过手性催化squaramide 10。分离具有相邻四级-三级中心的产品,具有极高的收率(高达99%),高非对映选择性(高达11:1)和对映体纯度(高达92%)。这是在高度立体选择性的有机催化反应中将3-氯氧吲哚1用作亲核试剂的第一个例子。