Copper-catalyzed domino synthesis of nitrogen heterocycle-fused benzoimidazole and 1,2,4-benzothiadiazine 1,1-dioxide derivatives.

A convenient copper-catalyzed domino method for the synthesis of nitrogen heterocycle-fused benzoimidazole and 1,2,4-benzothiadiazine 1,1-dioxides has been developed using readily available 2-bromo-N-phenylbenzenesulfonamides and benzimidazole derivatives as the starting materials. The domino process comprises an Ullmann-type N-arylation and intramolecular C-H amination. The inexpensive and efficient copper-catalyzed method should provide a new and useful strategy for for constructing novel, biologically interesting heterocycles containing benzoimidazole and 1,2,4-benzothiadiazine 1,1-dioxide motifs.