A Novel Approach for C–C, C–N, and C–O Bond Formation Reactions: A Facile Synthesis of Benzophenazine, Quinoxaline, and Phenoxazine Derivatives via Ring Opening of Benzoxepines

A new one-pot protocol has been developed for the synthesis of benzophenazine, quinoxaline, and phenoxazine derivatives by the reaction of benzoxepine-4-carboxylates with benzene-1,2-diamines, ethane-1,2-diamine, and 2-aminophenols in the presence of Bi(OTf)3 (5 mol %) under mild conditions in very good yields. The present protocol opens a new way for C–C, C–N, and C–O bond-formation reactions in a single-step process. The structural assignment was confirmed by X-ray analysis.