One-Pot Synthesis of Fused Benzo[c]carbazoles by Photochemical Intramolecular Annulation of 3-Acyl-2-haloindoles with Tethered Styrenes

• Published in: European Journal of Organic Chemistry 2011-10, Vol.2011 (29), p.5905-5910
• Main Authors: Lu, Shen-Ci, Wei, Shi-Chao, Wang, Wei-Xia, Zhang, Wei, Tu, Zhi-Feng
• Format: Article
• Language: English
• Subjects: Aromatization; Benzo[c]carbazoles; C-C coupling; Chemistry; Exact sciences and technology; General and physical chemistry; Halogens; Heterocyclic compounds; Heterocyclic compounds with only one n hetero atom and condensed derivatives; Noncondensed benzenic compounds; Organic chemistry; Photochemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Preparations and properties; Styrenes
• ISSN: 1434-193X; 1099-0690
• 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. An efficient procedure for the synthesis of fused benzo[c]carbazoles has been achieved in moderate to high yields by a 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.