KOtBu-Promoted Oxidation of (Hetero)benzylic Csp3-H to Ketones with Molecular Oxygen

An efficient and practical (hetero)benzylic sp(3) C-H oxidation method has been developed. Notably, this user-friendly protocol employs inexpensive potassium tert-butoxide ((KOBu)-Bu-t) as a promoter and proceeds under mild conditions using oxygen as the oxidant. A large variety of oxidation products were prepared in good to excellent yields. The utility of this green methodology was further demonstrated by the scale-up preparation of a biologically valued molecule.