A General Organocatalytic Enantioselective Malonate Addition to α,β-Unsaturated Enones
作者:Veit Wascholowski、Kristian Rahbek Knudsen、Claire E. T. Mitchell、Steven V. Ley
DOI:10.1002/chem.200800673
日期:2008.7.7
A general enantioselective organocatalytic conjugate addition procedure of a variety of malonates to alpha,beta-unsaturated enone systems is presented. The reaction is efficiently catalysed by the pyrrolidinyl tetrazole catalyst 1. Cyclic, acyclic and aromatic enones can be used and the reaction with ethyl malonates 3 b provides the Michael addition products in high yields with good to excellent enantioselectivities
提出了各种丙二酸酯向α,β-不饱和烯酮体系的一般对映选择性有机催化共轭加成方法。该反应被吡咯烷基四唑催化剂1有效地催化。可以使用环状,无环和芳族烯酮,并且与丙二酸乙酯3b的反应以高收率提供了迈克尔加成产物,具有良好的至优异的对映选择性。由于仅使用1.5当量的丙二酸酯作为试剂,因此该反应易于规模化并且操作实用。此外,丙二酸酯加成产物可通过酶促或氢氧化钠介导的方法容易地单脱羧而不会损失对映体过量。