Research Progress in the Environmentally-Friendly Michael Addition

Michael addition is one kind of important reaction in the organic field. With the enhancement of environmental awareness and the depth of green chemistry research, environmentally-friendly Michael addition has made many successes. The research progress over the past 5 years in the Michael addition involving ionic liquids, enzyme catalysis, solid phase supported catalysis and polyethylene glycol (PEG) is reviewed. This paper is consisted of six parts, focusing on the efficiency of the reaction system, the probable catalytic mechanism and the recycle of the catalyst. In the first part, a brief introduction is given. Then the Michael addition used the ionic liquid as catalyst or/and solvent is elaborated. In this part, acidic ionic liquid, basic ionic liquids and chiral ionic liquid are described, respectively. As a mild catalyst, enzymes are described in the third part. The solid phase supported catalysis has been used in many reaction without exception to Michael addition. So, in the fourth part, the catalysts of polymer supported, silica-supported and superparamagnetic nano supported are stated. Following, the successful use of polyethylene glycol (PEG) as a green solvent is presented. Finally, the conclusion, the existing problems of these green technologies and the prospect are summarized.