title: Unprecedented regiochemical control in the formation of aryl[1,2-a]imidazopyridines from alkynyliodonium salts: mechanistic insights.
abstract: Aryl(alkynyl)iodonium salts have been demonstrated to be valuable precursors to a diverse range of heteroaromatic ring systems including aryl[1,2-a]imidazopyridines. Successful application, using the recently described aryl(alkynyl)iodonium trifluoroacetate salts, is described, highlighting for the first time that the regioselectivity of this process is both counter-ion and concentration dependent. Studies with a carbon-13 labelled substrate established that the reactions of alkynyliodonium salts are highly complex and that multiple mechanistic processes appear to be underway simultaneously.
authors.affiliation: School of Chemistry, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK. m.a.carroll@ncl.ac.uk.
authors.forename: Luke I
authors.initials: LI
authors.lastname: Dixon
authors.forename: Michael A
authors.initials: MA
authors.lastname: Carroll
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Gregson
authors.forename: George J
authors.initials: GJ
authors.lastname: Ellames
authors.forename: Ross W
authors.initials: RW
authors.lastname: Harrington
authors.forename: William
authors.initials: W
authors.lastname: Clegg