(P,C) Cyclometalated Gold(III) Complexes: Highly Active Catalysts for the Hydroarylation of Alkynes.

The first catalytic application of well-defined (P,C) cyclometalated gold(III) complexes is reported. The bench-stable bis(trifluoroacetyl) complexes 2 a,b perform very well in the intermolecular hydroarylation of alkynes. The reaction is broad in scope, it proceeds within few hours at 25 °C at catalytic loadings of 0.1-5 mol %. The electron-rich arene adds across the C≡C bond with complete regio- and stereo-selectivity. The significance of well-defined gold(III) complexes and ligand design are highlighted in a powerful but challenging catalytic transformation.