title: Cyclization of gold acetylides: synthesis of vinyl sulfonates via gold vinylidene complexes.
abstract: Differently substituted terminal alkynes that bear sulfonate leaving groups at an appropriate distance were converted in the presence of a propynyl gold(I) precatalyst. After initial formation of a gold acetylide, a cyclization takes place at the β-carbon atom of this species. Mechanistic studies support a mechanism that is related to that of dual gold-catalyzed reactions, but for the new substrates, only one gold atom is needed for substrate activation. After formation of a gold vinylidene complex, which forms a tight contact ion pair with the sulfonate leaving group, recombination of the two parts delivers vinyl sulfonates, which are valuable targets that can serve as precursors for cross-coupling reactions, for example.
authors.affiliation: Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg (Germany) http://www.hashmi.de.
authors.forename: Janina
authors.initials: J
authors.lastname: Bucher
authors.forename: Thomas
authors.initials: T
authors.lastname: Wurm
authors.forename: Kumara Swamy
authors.initials: KS
authors.lastname: Nalivela
authors.forename: Matthias
authors.initials: M
authors.lastname: Rudolph
authors.forename: Frank
authors.initials: F
authors.lastname: Rominger
authors.forename: A Stephen K
authors.initials: AS
authors.lastname: Hashmi
keywords: acetylides; alkynes; cyclization; gold; vinylidenes