I₂-promoted aerobic oxidative coupling of acetophenes with amines under metal-free conditions: Facile access to α-ketoamides

A novel and efficient I₂-promoted oxidative coupling of acetophenes with amines to α-ketoamides is presented, which employs O₂ as an environmentally friendly oxidant under metal-free conditions. Based on a series of control experiments and radical trapping experiments, plausible reaction mechanism was proposed and iminium ion was identified as a significant intermediate in this process. This methodology is a feasible, mild approach to α-ketoamides in good yields.