Rhodium(I)-Catalyzed Decarbonylative Aerobic Oxidation of Cyclic α-Diketones: A Regioselective Single Carbon Extrusion Strategy

A rhodium-catalyzed decarbonylative aerobic oxidation of cyclic alpha-diketones has been developed for the first time, where the regioselective formations of alpha-pyrones and isocoumarins have been achieved. The current decarbonylative aerobic oxidation pathway proceeds via the C-C bond cleavage followed by a C-O bond formation, representing a biomimetic oxidation approach to unsaturated six-membered cyclic lactones. The unique ability of rhodium catalysts to induce the decarbonylative aerobic oxidation opens up a new synthetic toolbox that utilizes the regioselective single carbon extrusion strategy.