A fast and highly efficient protocol for Michael addition of N-heterocycles to α,β-unsaturated compound using basic ionic liquid [bmIm]OH as catalyst and green solvent

A fast and green protocol for the Michael addition of N-heterocycles to alpha,beta-unsaturated compounds at room temperature was developed using a basic ionic liquid, 1-methyl-3-butylimidazolium hydroxide, [bmlm]OH, as a catalyst and a reaction medium. The reactions were performed at room temperature with good yields in short reaction times (0.5-3 h). This strategy is quite general and it works with a broad range of N-heterocycles, including five-membered N-heterocycles, pyrimidines and purines. The recovered ionic liquid could be reused for several cycles with consistent activity. (c) 2006 Elsevier Ltd. All rights reserved.