Enantioselective Michael reaction of nitroalkanes onto nitroalkenes catalyzed by cinchona alkaloid derivatives
摘要:
An effective asymmetric synthesis of optically active 1,3-dinitro compounds via the direct Michael addition of nitroalkanes onto nitroalkenes has been described. In the presence of readily modified cinchona alkaloid derivatives, nitroethane reacted well with a variety of aromatic and heterocyclic aromatic nitroalkenes to afford products with good diastereoselectivities (dr up to 72/28) and enantioselectivities (ee up to 94%). The catalyst loading can be decreased to 2 mol % without compromising the asymmetric induction or the reaction rate. (C) 2012 Elsevier Ltd. All rights reserved.
The Development of the First Catalyzed Reaction of Ketenes and Imines: Catalytic, Asymmetric Synthesis of β-Lactams
作者:Andrew E. Taggi、Ahmed M. Hafez、Harald Wack、Brandon Young、Dana Ferraris、Thomas Lectka
DOI:10.1021/ja0258226
日期:2002.6.1
resulting from the development of a catalyzed reaction of ketenes (or their derived zwitterionic enolates) and imines. The products of these asymmetric reactions can serve as precursors to a number of enzyme inhibitors and drug candidates as well as valuable synthetic intermediates. We present a detailed study of the mechanism of the beta-lactam forming reaction with proton sponge as the stoichiometric
Enantioselective Michael reaction of nitroalkanes onto nitroalkenes catalyzed by cinchona alkaloid derivatives
作者:Yan-Qiu Deng、Zhen-Wei Zhang、Ya-Hui Feng、Albert S.C. Chan、Gui Lu
DOI:10.1016/j.tetasy.2012.11.008
日期:2012.12
An effective asymmetric synthesis of optically active 1,3-dinitro compounds via the direct Michael addition of nitroalkanes onto nitroalkenes has been described. In the presence of readily modified cinchona alkaloid derivatives, nitroethane reacted well with a variety of aromatic and heterocyclic aromatic nitroalkenes to afford products with good diastereoselectivities (dr up to 72/28) and enantioselectivities (ee up to 94%). The catalyst loading can be decreased to 2 mol % without compromising the asymmetric induction or the reaction rate. (C) 2012 Elsevier Ltd. All rights reserved.