Rhodium(III)‐Catalyzed (5+2) Annulation Reaction for the Synthesis of Nitro and Cyano Substituted Benzo[b]Oxepines

A Rh(III)‐catalyzed annulation reaction of 2‐(2‐nitrovinyl)phenols and disubstituted alkynes is developed to complete the first synthesis of biologically important 4‐nitro substituted benzo[ b ]oxepines. The same reaction conditions are also applied for the efficient synthesis of 4‐cyano substituted benzo[ b ]oxepines which have high biological significance. Some of the synthesized 4‐nitrobenzo[ b ]oxepines are easily transformed to triazole fused dibenzo[ b ]oxepines.