Acidic-functionalized ionic liquid as an efficient, green and reusable catalyst for hetero-Michael addition of nitrogen, sulfur and oxygen nucleophiles to α,β-unsaturated ketones

Abstract

A series of acidic-functionalized ionic liquids were synthesized and applied to the hetero-Michael addition of nitrogen, sulfur and oxygen nucleophiles to α,β-unsaturated ketones under solvent-free conditions. Notably, 1-methylimidazolium p-toluenesulfonic ([Hmim]OTs) was found to be the most efficient catalyst and could realize "homogeneous catalysis, two-phase separation". Additionally, the catalytic system has wide substrate scope and good to excellent yields (up to 99%) could be obtained at room temperature.