A General, Brønsted Acid-Catalyzed Hetero-Michael Addition of Nitrogen, Oxygen, and Sulfur Nucleophiles

Abstract
Strong Brønsted acids such as bis(trifluoromethanesulfon)imide catalyze the hetero-Michael addition of carbamates, alcohols, and thiols to α,β-unsaturated ketones, alkylidene malonates, and acrylimides. Scope, reaction rates, and yields are superior to comparable Lewis acid-catalyzed processes.