title: A bonding model for gold(I) carbene complexes.
abstract: The last decade has witnessed dramatic growth in the number of reactions catalyzed by electrophilic gold complexes. While proposed mechanisms often invoke the intermediacy of gold-stabilized cationic species, the nature of bonding in these intermediates remains unclear. Herein, we propose that the carbon-gold bond in these intermediates is comprised of varying degrees of both sigma and pi-bonding; however, the overall bond order is generally less than or equal to unity. The bonding in a given gold-stabilized intermediate, and the position of this intermediate on a continuum ranging from gold-stabilized singlet carbene to gold-coordinated carbocation, is dictated by the carbene substituents and the ancillary ligand. Experiments show that the correlation between bonding and reactivity is reflected in the yield of gold-catalyzed cyclopropanation reactions.
authors.affiliation: Materials and Process Simulation Center, California Institute of Technology, Pasadena, California 91125 USA.
authors.forename: Diego
authors.initials: D
authors.lastname: Benitez
authors.forename: Nathan D
authors.initials: ND
authors.lastname: Shapiro
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Tkatchouk
authors.forename: Yiming
authors.initials: Y
authors.lastname: Wang
authors.forename: William A
authors.initials: WA
authors.lastname: Goddard
authors.forename: F Dean
authors.initials: FD
authors.lastname: Toste
mesh_terms: D003521:Cyclopropanes / Q000138:chemical synthesis / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D008024:Ligands; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D015394:Molecular Structure; D050607:Organogold Compounds / Q000737:chemistry*
chemical_list: D003521:Cyclopropanes; D008024:Ligands; D050607:Organogold Compounds; C030011:carbene; D006046:Gold; D008697:Methane