N-Heterocyclic Carbene (NHC)-Catalyzed Intramolecular Benzoin Condensation‒Oxidation

NHC-Catalyzed intramolecular benzoin condensation–oxidation is developed for the expedient synthesis of diverse cyclic 1,2-diketones incorporated in dibenzo-fused seven-membered heterocycles in good to excellent yields, under ambient conditions. The presented carbene-catalyzed transformation appears to proceed through the benzoin intermediate followed by aerobic oxidation.