Manganese Dioxide–Methanesulfonic Acid Promoted Direct Dehydrogenative Alkylation of sp3C–H Bonds Adjacent to a Heteroatom

A manganese dioxide (MnO2)–methanesulfonic acid (CH3SO3H) oxidation system has been developed to efficiently promote direct coupling of benzylic ethers and carbamates with simple ketones via oxidative C–H bond activation. The alkylation proceeds smoothly under air atmosphere to afford the corresponding products in good to excellent yields (53–87%). The employment of the combination of MnO2 and CH3SO3H is attractive on the basis of economical and environmental issues.