Study on the Pd/C-Catalyzed (Retro-)Michael Addition Reaction of Activated Methylene Compounds to Electron-Poor Styrenes
作者:Nicolai I. Nikishkin、Jurriaan Huskens、Willem Verboom
DOI:10.1002/ejoc.201000961
日期:2010.12
(10% Pd/C) efficiently catalyzes the (retro-)Michael addition of activated methylene compounds 2a-d, such as malononitrile (2b), to mono- and doubly activated styrenes 1a-h to give the adducts 3a-1. The scope and limitations are described. The Knoevenagel condensation reaction of benzaldehyde and 2b or ethyl cyanoacetate (2c) is also catalyzed by 10 % Pd/C. In these cases the Michael adducts can even
钯碳(10% Pd/C)有效地催化活化亚甲基化合物 2a-d(例如丙二腈 (2b))与单和双活化苯乙烯 1a-h 的(逆向)迈克尔加成反应,得到加合物 3a- 1. 描述了范围和限制。苯甲醛与 2b 或氰基乙酸乙酯 (2c) 的 Knoevenagel 缩合反应也由 10% Pd/C 催化。在这些情况下,迈克尔加合物甚至可以在三组分反应中制备。提出了一种机制,第一步是将 2a-d 氧化加成到 Pd 0 上。