DMSO-Promoted Metal-free Aerobic Oxidation of Heterobenzylic Methylene to Prepare the N-Heterocyclic Ketones

Using O-2 as the terminal oxidant, the direct oxygenation of heterobenzylic C-H bonds can be achieved in DMSO. Various N-heteroaryl ketones were provided with good yields through the protocol. It can also be conducted on a gram scale with good reaction efficiency. DMSO plays an important role in this selective oxygenation reaction of heterobenzylic methylenes.