title: Stable gold(III) catalysts by oxidative addition of a carbon-carbon bond.
abstract: Low-valent late transition-metal catalysis has become indispensable to chemical synthesis, but homogeneous high-valent transition-metal catalysis is underdeveloped, mainly owing to the reactivity of high-valent transition-metal complexes and the challenges associated with synthesizing them. Here we report a carbon-carbon bond cleavage at ambient conditions by a Au(i) complex that generates a stable Au(iii) cationic complex. In contrast to the well-established soft and carbophilic Au(i) catalyst, this Au(iii) complex exhibits hard, oxophilic Lewis acidity. For example, we observed catalytic activation of α,β-unsaturated aldehydes towards selective conjugate additions as well as activation of an unsaturated aldehyde-allene for a [2 + 2] cycloaddition reaction. The origin of the regioselectivity and catalytic activity was elucidated by X-ray crystallographic analysis of an isolated Au(iii)-activated cinnamaldehyde intermediate. The concepts revealed suggest a strategy for accessing high-valent transition-metal catalysis from readily available precursors.
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720, USA.
authors.forename: Chung-Yeh
authors.initials: CY
authors.lastname: Wu
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720, USA.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Horibe
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720, USA.
authors.forename: Christian Borch
authors.initials: CB
authors.lastname: Jacobsen
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720, USA.
authors.forename: F Dean
authors.initials: FD
authors.lastname: Toste
mesh_terms: D000171:Acrolein / Q000031:analogs & derivatives / Q000737:chemistry; D000447:Aldehydes / Q000737:chemistry; D000466:Alkadienes / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D002384:Catalysis; D018360:Crystallography, X-Ray; D006046:Gold / Q000737:chemistry*; D058116:Lewis Acids / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D010084:Oxidation-Reduction
chemical_list: D000447:Aldehydes; D000466:Alkadienes; D058116:Lewis Acids; C025947:propadiene; D002244:Carbon; D006046:Gold; D000171:Acrolein; C012843:cinnamaldehyde