title: A new route to α-carbolines based on 6π-electrocyclization of indole-3-alkenyl oximes.
abstract: Indoles are converted into α-carbolines in four steps by acylation at C-3, Boc-protection, olefination of the resulting 3-indolyl aldehydes or ketones to give N-Boc-3-indolyl alkenyl oxime O-methyl ethers, which upon heating to 240 °C under microwave irradiation undergo loss of the Boc-group, and 6π-electrocyclization to α-carbolines, following aromatization by loss of methanol (11 examples, 30-90% yield).
authors.affiliation: School of Chemistry, University of Nottingham , Nottingham NG7 2RD, U.K.
authors.forename: Sophie J
authors.initials: SJ
authors.lastname: Markey
authors.forename: William
authors.initials: W
authors.lastname: Lewis
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Moody
mesh_terms: D002243:Carbolines / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003500:Cyclization; D004583:Electrons; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D010091:Oximes / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D002243:Carbolines; D007211:Indoles; D010091:Oximes