Enantioselective cyclopropanation of enals by oxidative N-heterocyclic carbene catalysis
作者:Anup Biswas、Suman De Sarkar、Ludger Tebben、Armido Studer
DOI:10.1039/c2cc31501g
日期:——
Carbene catalysed redox activation of alpha,beta-unsaturated aldehydes is applied for generation of alpha,beta-unsaturated acyl azoliums which undergo cyclopropanation upon reaction with a sulfur ylide and an alcohol to give the corresponding cyclopropanecarboxylic acid esters. With chiral carbenes good to excellent diastereo and enantioselectivities are obtained.
碳催化的α,β-不饱和醛的氧化还原活化被用于产生α,β-不饱和酰基偶氮,其在与硫内酯和醇反应后进行环丙烷化,得到相应的环丙烷羧酸酯。使用手性碳烯,可以获得极佳的非对映异构性和对映选择性。