title: Formation of Cyclohepta[b]indole Scaffolds via Heck Cyclization: A Strategy for Structural Analogues of Ervatamine Group of Indole Alkaloid.
abstract: Ervatamine, silicine, methuenine, etc., are naturally occurring alkaloids that exhibit antimicrobial, anticancer, and anti-HIV activities. Indole fused with a seven-membered carbocyclic ring is a commonly observed structural feature among this series of bioactive compounds. This work describes a strategic approach for the synthesis of cyclohepta[b]indole structural scaffolds. The synthetic strategy consists of a solvent-free Baylis-Hillman reaction of 2-bromobenzaldehydes, followed by iodine-catalyzed C-alkylation of indole with the Baylis-Hillman adducts. Finally, intramolecular Heck coupling reaction using Pd(OAc)2 as catalyst in the presence of benzyltrimethylammonium bromide under microwave condition produced the desired cyclohepta[b]indole derivatives.
authors.affiliation: Department of Chemistry, Gauhati University, Guwahati, 781014 Assam, India.
authors.forename: Progyashree
authors.initials: P
authors.lastname: Goswami
authors.affiliation: Department of Chemistry, Gauhati University, Guwahati, 781014 Assam, India.
authors.forename: Arun Jyoti
authors.initials: AJ
authors.lastname: Borah
authors.affiliation: Department of Chemistry, Gauhati University, Guwahati, 781014 Assam, India.
authors.forename: Prodeep
authors.initials: P
authors.lastname: Phukan
mesh_terms: D018360:Crystallography, X-Ray; D003500:Cyclization; D003546:Cysteine Endopeptidases / Q000737:chemistry*; D026121:Indole Alkaloids / Q000737:chemistry*; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure
chemical_list: D026121:Indole Alkaloids; D007211:Indoles; C000599575:cyclohepta(b)indole; D003546:Cysteine Endopeptidases; C116225:ervatamin