title: Chemoselective Sequential Click Ligations Directed by Enhanced Reactivity of an Aromatic Ynamine.
abstract: Aromatic ynamines or N-alkynylheteroarenes are highly reactive alkyne components in Cu-catalyzed Huisgen [3 + 2] cycloaddition ("click") reactions. This enhanced reactivity enables the chemoselective formation of 1,4-triazoles using the representative aromatic ynamine N-ethynylbenzimidazole in the presence of a competing aliphatic alkyne substrate. The unique chemoselectivity profile of N-ethynylbenzimidazole is further demonstrated by the sequential click ligation of a series of highly functionalized azides using a heterobifunctional diyne, dispelling the need for alkyne protecting groups.
authors.affiliation: Department of Pure and Applied Chemistry, WestCHEM, University of Strathclyde , Glasgow, G1 1XL, U.K.
authors.forename: Marine Z C
authors.initials: MZ
authors.lastname: Hatit
authors.affiliation: Department of Pure and Applied Chemistry, WestCHEM, University of Strathclyde , Glasgow, G1 1XL, U.K.|GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, U.K.
authors.forename: Joanna C
authors.initials: JC
authors.lastname: Sadler
authors.affiliation: Department of Pure and Applied Chemistry, WestCHEM, University of Strathclyde , Glasgow, G1 1XL, U.K.
authors.forename: Liam A
authors.initials: LA
authors.lastname: McLean
authors.affiliation: Department of Pure and Applied Chemistry, WestCHEM, University of Strathclyde , Glasgow, G1 1XL, U.K.|GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, U.K.
authors.forename: Benjamin C
authors.initials: BC
authors.lastname: Whitehurst
authors.affiliation: Department of Pure and Applied Chemistry, WestCHEM, University of Strathclyde , Glasgow, G1 1XL, U.K.
authors.forename: Ciaran P
authors.initials: CP
authors.lastname: Seath
authors.affiliation: GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, U.K.
authors.forename: Luke D
authors.initials: LD
authors.lastname: Humphreys
authors.affiliation: GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, U.K.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Young
authors.affiliation: Department of Pure and Applied Chemistry, WestCHEM, University of Strathclyde , Glasgow, G1 1XL, U.K.
authors.forename: Allan J B
authors.initials: AJ
authors.lastname: Watson
authors.affiliation: Department of Pure and Applied Chemistry, WestCHEM, University of Strathclyde , Glasgow, G1 1XL, U.K.
authors.forename: Glenn A
authors.initials: GA
authors.lastname: Burley