Metal-free TEMPO-catalyzed oxidative C–C bond formation from Csp3–H bonds using molecular oxygen as the oxidant

An efficient TEMPO-catalyzed oxidative C-C bond formation with two Csp(3)-H bonds using molecular oxygen as the oxidant has been developed. The novel transformation provides a new strategy for the TEMPO-O(2) catalysis to construct C-C bonds. The advantages of this method include: (1) relatively mild and neutral conditions; (2) simplicity and safety of operation; (3) a stoichiometric amount of dangerous oxidants, any transition metals, additives, even solvent, is not required.