title: Direct Electrophilic C-H Alkynylation of Unprotected 2-Vinylanilines.
abstract: Unprotected aromatic amines can be used as directing groups in metal-catalyzed C-H alkynylations of alkenes. By using low amounts of an IrIIIcatalyst in combination with alkynylbenziodoxolones as electrophilic alkyne-transfer reagents, highly desirable 1,3-enynes were isolated in excellent yields of up to 98 % with Z stereoselectivity. A broad substrate scope as well as the high synthetic utility of the 1,3-enynes render this new method an efficient approach for the synthesis of five- and six-membered heterocycles. Further derivatizations of the 1,3-enynes to highly substituted quinolines through AuI- and N-bromosuccinimide-mediated exo-dig cyclizations were demonstrated.
authors.affiliation: Institut für Organische und Analytische Chemie, Universität Bremen, Leobener Straße NW2C, 28359, Bremen, Germany.
authors.forename: Lucien D
authors.initials: LD
authors.lastname: Caspers
authors.affiliation: Department of Chemistry, University of California, Berkeley, Berkeley, California, 94720, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Finkbeiner
authors.affiliation: Institut für Organische und Analytische Chemie, Universität Bremen, Leobener Straße NW2C, 28359, Bremen, Germany.
authors.forename: Boris J
authors.identifier: http://orcid.org/0000-0002-3759-2770
authors.initials: BJ
authors.lastname: Nachtsheim
keywords: C−H activation; alkynes; enynes; iodine; iridium