One-pot synthesis of fused benzo[c]carbazoles by photochemical intramolecular annulation of 3-acyl-2-haloindoles with tethered styrenes

Article abstract of DOI:10.1002/ejoc.201100876

An efficient procedure for the synthesis of fused benzo[c]carbazoles has been achieved in moderate to high yields by the one-pot photochemical annulation of 3-acyl-2-haloindoles with tethered styrenes by photoinduced electron-transfer coupling, electrocyclic reactions, and deacylative aromatization in the presence of pyridine. Fused furo[2,3-c]carbazoles were also synthesized under the same conditions. 5,6-Dihydrobenzo[c]pyrrolo[1,2,3-lm] carbazoles were oxidized by DDQ to afford aromatic benzo[c]pyrrolo[1,2,3-lm] carbazole products in moderate to high yields.