Visible-Light Photocatalytic Multicomponent Ritter-Type Reactions with Aryl and Alkyl Bromides as Carbon Radical Precursors

We report a visible-light-mediated, multicomponent Ritter-type reaction among an alkene, an aryl or alkyl bromide, a carboxylic acid, acetonitrile, and water. These reactions lead to the 1,2-difunctionalization of alkenes to give a wide variety of N-substituted diacylimides. Importantly, aryl bromides are successfully used as an aryl radical source in these reactions, significantly enhancing the structural diversity of the N-substituted diacylimide products of potential biological value. On the basis of control experiments and computation of the energy profile of the reaction, the role of carboxylate and water in the reaction was clarified and a reaction mechanism was proposed.