title: Intramolecular hydroamination of alkynic sulfonamides catalyzed by a gold-triethynylphosphine complex: Construction of azepine frameworks by 7-exo-dig cyclization.
abstract: The gold-catalyzed, seven-membered ring forming, intramolecular hydroamination of alkynic sulfonamides has been investigated. The protocol, with a semihollow-shaped triethynylphosphine as a ligand for gold, allowed the synthesis of a variety of azepine derivatives, which are difficult to access by other methods. Both alkynic sulfoamides with a flexible linear chain and the benzene-fused substrates underwent 7-exo-dig cyclization to afford the nitrogen-containing heterocyclic seven-membered rings, such as tetrahydroazepine and dihydrobenzazepine, in good yields.
authors.affiliation: Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan.
authors.forename: Hideto
authors.initials: H
authors.lastname: Ito
authors.forename: Tomoya
authors.initials: T
authors.lastname: Harada
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Ohmiya
authors.forename: Masaya
authors.initials: M
authors.lastname: Sawamura