Asymmetric Michael Addition of α-Hydroxyketones to Nitroolefins Catalyzed by Chiral Diamine
作者:Olivier Andrey、Alexandre Alexakis、Gérald Bernardinelli
DOI:10.1021/ol0348755
日期:2003.7.1
[GRAPHIC]The regio-, stereo-, and enantioselective direct Michael addition of alpha-hydroxyketones to beta-aryinitroolef ins catalyzed by N-/Pr-2,2'-bipyrrolidine is described. The formation of an internal hydrogen bond between the OH group of alpha-hydoxyacetone and the tertiary nitrogen of the catalyst leads to the formation of a rigid cis enamine intermediate that explains the inversion of the expected diastereoselectivity and the very high ee's.