N-Bromosuccinimide–carboxylic acid combination: mild and efficient access to dibromination of unsaturated carbonyl compounds

A mild, efficient and practical method for the preparation of dihalogenated products has been developed. Benzoic acid (0.2 equiv.) is capable of catalyzing the reactions of unsaturated carbonyl compounds with N-halosuccinimides (NXS, X = Br and Cl) to afford a series of dihalogenated products at room temperature.