title: Allenyl azide cycloaddition chemistry. 2,3-cyclopentennelated indole synthesis through indolidene intermediates.
abstract: The thermal, photochemical, and photochemical/CuI-mediated cascade cyclizations of a range of substituted 1-(2-azidophenyl)-3-alkenylallenes are described. These reactions provide both 1,2- and 2,3-cyclopentennelated indole products in varying ratios. In most cases, high regioselectivity for the 2,3-annelated isomer can be achieved under the hnu/CuI conditions. Computational studies of this multistep reaction support the intermediacy of indolidene intermediates whose electrocyclizations (with or without copper present) define the regioselectivity branch point in the sequence.
authors.affiliation: Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA. ksf@chem.psu.edu
authors.forename: Ken S
authors.initials: KS
authors.lastname: Feldman
authors.forename: D Keith
authors.initials: DK
authors.lastname: Hester
authors.forename: Malliga R
authors.initials: MR
authors.lastname: Iyer
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Munson
authors.forename: Carlos
authors.initials: C
authors.lastname: Silva López
authors.forename: Olalla Nieto
authors.initials: ON
authors.lastname: Faza
mesh_terms: D001386:Azides / Q000737:chemistry*; D003198:Computer Simulation; D003300:Copper / Q000737:chemistry; D003500:Cyclization; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D008027:Light; D015394:Molecular Structure; D013237:Stereoisomerism; D013816:Thermodynamics
chemical_list: D001386:Azides; D007211:Indoles; D003300:Copper