作者:Anniina Erkkilä、Petri M. Pihko
DOI:10.1002/ejoc.200700292
日期:2007.9
We report the results of the systematic optimization of the α-methylenation of aldehydes with aqueous formaldehyde. A simple combination of a secondary amine catalyst and a weak acid co-catalyst has been identified, allowing access to α-substituted acroleins in a matter of minutes. In the absence of formaldehyde, the catalytic system promoted the self-condensation reaction of α,β-unsaturated aldehydes
我们报告了醛类与甲醛水溶液的 α-甲基化的系统优化结果。已经确定了仲胺催化剂和弱酸助催化剂的简单组合,可以在几分钟内获得 α-取代的丙烯醛。在没有甲醛的情况下,催化体系促进了 α,β-不饱和醛的自缩合反应。这两个反应都表现出助催化剂酸度和反应速率之间的线性关系。观察到催化剂浓度的二级依赖性,表明在速率确定步骤中涉及两个铵催化剂分子。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)