FeCl 3 catalysed 7-membered ring formation in a single pot: a new route to indole-fused oxepines/azepines and their cytotoxic activity

. The reaction proceeded via C-C bond followed by C-X (X = O or N) bond formation to construct the central 7-membered ring, affording the desired products in good yields. The structure assignment was confirmed by the single crystal X-ray analysis of a synthesized oxepine fused N-heterocycle derivative. Most of the synthesized compounds were found to be promising when tested for their anti-proliferative properties against cervical and breast cancer cell lines.