Transition-metal-catalyzed, directed intermolecular C−H bond functionalization is synthetically useful but heavily underexplored in multiheteroatom heterocycle synthesis. Herein we report a cobalt catalytic method for the formation of a threenitrogen-bearing benzotriazine scaffold via the coupling of arylhydrazine and oxadiazolone. This synthetic protocol features a lowcost base metal catalyst, a maximum number of heteroatoms built into a heterocycle, a distinct synthetic logic for benzotriazines, a superior step economy, and a broad substrate scope.

Previous transition metal-catalyzed synthesis of δ-diketones is plagued by high cost of rhodium catalyst and harsh reaction conditions. Herein a low-cost, room temperature ruthenium catalytic method is developed based on...