title: The influence of the ligand chelate effect on iron-amine-catalysed Kumada cross-coupling.
abstract: The application of a variety of iron complexes with chelating amine ligands as pre-catalysts in the representative cross-coupling of 4-tolylmagnesium bromide with cyclohexyl bromide was investigated. The results from this study indicate the performance of the pre-catalyst is inversely proportional to the strength of the chelate or macrocyclic effect of the amine ligand, as determined by the propensity of the ligand to be displaced from the iron centre by reaction with excess benzyl magnesium chloride. The findings from this study are consistent with a catalytic cycle wherein the chelating amine ligand is not coordinated to the iron centre during turnover.
authors.affiliation: School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK. r.bedford@bristol.ac.uk.
authors.forename: Robin B
authors.initials: RB
authors.lastname: Bedford
authors.affiliation: School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK. r.bedford@bristol.ac.uk.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Brenner
authors.affiliation: School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK. r.bedford@bristol.ac.uk.
authors.forename: David
authors.initials: D
authors.lastname: Elorriaga
authors.affiliation: Quantum Chemistry and Physical Chemistry Section, Department of Chemistry, University of Leuven (KU Leuven), Celestijnenlaan 200F - box 2404, Leuven, Belgium.
authors.forename: Jeremy N
authors.initials: JN
authors.lastname: Harvey
authors.affiliation: School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK. r.bedford@bristol.ac.uk.
authors.forename: Joshua
authors.initials: J
authors.lastname: Nunn