Conjugated imines and iminium salts as versatile acceptors of nucleophiles
作者:Makoto Shimizu、Iwao Hachiya、Isao Mizota
DOI:10.1039/b814930e
日期:——
development of synthetic methodologies where nucleophilicaddition reactions to imino carbons are utilized in crucial steps. This article summarizes double nucleophilicaddition reactions with alpha,beta-unsaturated aldimines, addition reactions using alkynyl imines, "umpoled" reactions of alpha-imino esters, and the use of iminium salts as reactive electrophiles.
enantioselectivities (up to 96% ee). The present study describes the first successful examples of asymmetricconjugateaddition reactions of α-cyanoketones with benzoyl acrylonitriles. In addition, the DMM organocatalyst can be recovered and reused up to five times without significant loss of either catalytic activity or enantioselectivity. Publication History Received: 28 July 2020 Accepted after revision: 20 August
reactions, giving the corresponding 2,2-disubstituted-3-cyclohexenone derivatives in a completely regioselective manner. This newly developed methodology has been successfully applied towards the totalsynthesis, in racemic form, of the marine natural product nanaimoal.
Enantioselective Synthesis of Cyclic, Quaternary Oxonitriles
作者:Yakup Güneş、M. Fatih Polat、Ertan Sahin、Fraser F. Fleming、Ramazan Altundas
DOI:10.1021/jo1011202
日期:2010.11.5
Quaternaryoxonitriles are stereoselectively generated from the union of five-, six-, and seven-membered 2-chloroalkenecarbonitriles with chiral alcohols via a Claisen rearrangement. The strategy rests on a new conjugate addition−elimination of allylic alkoxides to 2-chlorocycloalkenecarbonitriles to afford substituted 2-alkoxyalkenenitriles. Subsequent thermolysis unmasks a cyclicoxonitrile while
Catalytic enantioselective conjugate additions with α,β-unsaturated sulfones
作者:Hongming Li、Jun Song、Li Deng
DOI:10.1016/j.tet.2008.11.054
日期:2009.4
development of a highlyefficient catalytic asymmetric conjugate addition to α,β-unsaturated sulfones. Utilizing practical bifunctional organic catalysts and involving air- and moisture-tolerant conditions, conjugate additions of a wide range of Michael donors to α,β-unsaturated sulfones proceeded in excellent enantioselectivity/diastereoselectivity and high yield. This efficient and operationally