title: Intermediacy of an N-heterocyclic carbene complex in the catalytic C-H activation of a substituted benzimidazole.
abstract: An N-heterocyclic carbene complex was found to be the active catalyst in the Rh(I)-catalyzed intramolecular coupling of an alkenyl group to a C-H bond of a substituted benzimidazole. Kinetic studies demonstrated that the catalytic cyclization is zero-order in substrate and first-order in catalyst. Furthermore, DFT calculations with a model system suggest that the rate-limiting step involves insertion of the alkenyl double bond into the rhodium-carbene bond.
authors.affiliation: Center for New Directions in Synthesis, Department of Chemistry, University of California-Berkeley, Berkeley, CA 94720, USA.
authors.forename: Kian L
authors.initials: KL
authors.lastname: Tan
authors.forename: Robert G
authors.initials: RG
authors.lastname: Bergman
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Ellman
mesh_terms: D001562:Benzimidazoles / Q000737:chemistry*; D002384:Catalysis; D006838:Hydrocarbons; D007700:Kinetics; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D001562:Benzimidazoles; D006838:Hydrocarbons; C030011:carbene; D008697:Methane