Visible-Light-Induced Photocatalytic Deoxygenative Benzylation of Quinoxalin-2-(1)-ones with Carboxylic Acid Anhydrides.

A visible-light-induced photocatalytic deoxygenative benzylation of quinoxalin-2-(1)-ones is herein described. This novel approach provides a mild, simple, and practical route to 3-benzylquinoxalin-2(1)-ones from ubiquitous and safe carboxylic acid anhydrides. A wide range of substrates with different substituents were well-tolerated and efficiently transformed to various functionalized 3-benzylquinoxalin-2(1)-ones with great potential for valuable applications in drug discovery. Mechanistic investigations suggest HO as a proton source, while hydroxyl-containing quinoxalin-2(1)-ones may be key intermediates of the photocatalytic deoxygenative process.