Iodine-catalyzed Michael addition of mercaptans to α,β-unsaturated ketones under solvent-free conditions

A simple and efficient method for the Michael reaction between various mercaptans and α,β-unsaturated ketones using a catalytic amount of iodine (5 mol %) to generate the 1,4-adduct has been reported. The significant features of the iodine catalyzed Michael addition are (a) operational simplicity, (b) inexpensive reagents, (c) high yields of products, (d) the use of relatively low or nontoxic reagents and (e) solvent-free conditions.