title: Double Deprotonation of Pyridinols Generates Potent Organic Electron-Donor Initiators for Haloarene-Arene Coupling.
abstract: Transition metal-free couplings of haloarenes with arenes, triggered by the use of alkali metal alkoxides in the presence of an organic additive, are receiving significant attention in the literature. Most of the known organic additives effect coupling of iodoarenes, but not bromoarenes, to arenes. Recently it was reported that 2-pyridinecarbinol (11) extends the reaction to aryl bromides. This paper investigates the mechanism, and reports evidence for dianions derived from 11 as electron donors to initiate the reaction. It also proposes routes by which electron-poor benzoyl derivatives can be transformed into electron donors to initiate these reactions.
authors.affiliation: WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.|GlaxoSmithKline Medicines Research Centre, Gunnels Wood Road, Stevenage, SG1 2NY, UK.
authors.forename: Joshua P
authors.initials: JP
authors.lastname: Barham
authors.affiliation: WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.
authors.forename: Graeme
authors.initials: G
authors.lastname: Coulthard
authors.affiliation: WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.
authors.forename: Ryan G
authors.initials: RG
authors.lastname: Kane
authors.affiliation: WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.
authors.forename: Nathan
authors.initials: N
authors.lastname: Delgado
authors.affiliation: GlaxoSmithKline Medicines Research Centre, Gunnels Wood Road, Stevenage, SG1 2NY, UK.
authors.forename: Matthew P
authors.initials: MP
authors.lastname: John
authors.affiliation: WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK. john.murphy@strath.ac.uk.
authors.forename: John A
authors.identifier: http://orcid.org/0000-0003-3136-0845
authors.initials: JA
authors.lastname: Murphy
keywords: arenes; cross-coupling; electron transfer; radicals; reaction mechanisms