title: Regioselective π-extension of indoles with rhodium enalcarbenoids--synthesis of substituted carbazoles.
abstract: An efficient Rh(II) carboxylate and Brønsted acid catalyzed direct π-extension of indoles to 4-substituted carbazoles is developed. The reaction involves a regioselective C-3 functionalization of indole by a rhodium enalcarbenoid and a Brønsted acid assisted cyclocondensation. In addition a twofold regioselective π-extension of pyrroles to 4,8-disubstituted carbazoles has also been developed. The utility of the methodology was demonstrated with the synthesis of analogues of an hepatitis C virus replication inhibitor and a secreted phospholipase A2 (sPLA2) inhibitor.
authors.affiliation: Department of Chemistry, Indian Institute of Science Education & Research, Bhopal, Madhya Pradesh 462066, India. sk@iiserb.ac.in.
authors.forename: Kuldeep Singh
authors.initials: KS
authors.lastname: Rathore
authors.forename: Mandeep
authors.initials: M
authors.lastname: Harode
authors.forename: Sreenivas
authors.initials: S
authors.lastname: Katukojvala
mesh_terms: D000998:Antiviral Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D002227:Carbazoles / Q000138:chemical synthesis* / Q000494:pharmacology; D002264:Carboxylic Acids / Q000737:chemistry*; D002384:Catalysis; D016174:Hepacivirus / Q000187:drug effects / Q000502:physiology; D007211:Indoles / Q000737:chemistry*; D015394:Molecular Structure; D064801:Phospholipase A2 Inhibitors / Q000138:chemical synthesis* / Q000494:pharmacology; D054467:Phospholipases A2 / Q000378:metabolism; D011758:Pyrroles / Q000737:chemistry; D012238:Rhodium / Q000737:chemistry*; D013237:Stereoisomerism; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D002227:Carbazoles; D002264:Carboxylic Acids; D007211:Indoles; D064801:Phospholipase A2 Inhibitors; D011758:Pyrroles; D012238:Rhodium; D054467:Phospholipases A2