Asymmetric conjugate hydrocyanation of α,β-unsaturated carboxylic acid derivatives catalyzed by a Ru[(S)-phgly]2[(S)-binap]–CH3OLi system was examined. The N-acylpyrrole gave the best result in terms of reactivity and enantioselectivity. A series of substrates with alkyl or heterosubstituted alkyl groups at the β-position reacted with a substrate-to-catalyst molar ratio of 200–2000 to afford the β-cyano
Asymmetric Sulfa-Michael Addition of α,β-Unsaturated Esters/Amides Using a Chiral N-Heterocyclic Carbene as a Noncovalent Organocatalyst
作者:Jiean Chen、Yong Huang、Pengfei Yuan、Sixuan Meng
DOI:10.1055/s-0035-1561843
日期:——
We report an asymmetric sulfa-Michael reaction of α,β-unsaturated amides and estersusing a chiral N-heterocyclic carbene as the HOMO-raising organocatalyst. We discovered an interesting correlation between 13C NMR shifts of substrates and ee of their products. More electron-deficient Michael acceptors afforded higher enantioselectivity.
我们报告了使用手性 N-杂环卡宾作为 HOMO 提升有机催化剂的 α,β-不饱和酰胺和酯的不对称磺胺-迈克尔反应。我们发现底物的 13C NMR 位移与其产物的 ee 之间存在有趣的相关性。更多缺电子迈克尔受体提供更高的对映选择性。
Design, synthesis, and application of chiral electron-poor guanidines as hydrogen-bonding catalysts for the Michael reaction
作者:Karen Thai、Michel Gravel
DOI:10.1016/j.tetasy.2010.04.033
日期:2010.4
The first chiral electron-poor guanidine organocatalysts were synthesized. The presence of a tunable electron-withdrawing group on the guanidine moiety allows for the modulation of the catalysts' activity. The application of this new class of organocatalysts to the Michael reaction is demonstrated. (C) 2010 Elsevier Ltd. All rights reserved.
POLYMERS DERIVED FROM N-VINYL FORMAMIDE, VINYL AMIDES OR ACRYLAMIDES, AND REACTION SOLVENT, AND THE USES THEREOF