Organometallic chemistry in aqua regia: metal and ligand based oxidations of (NHC)AuCl complexes

The synthesis and characterization of a series of N-heterocyclic carbene (NHC) complexes of Au(III), (NHC)AuCl3, is described. High yields are obtained when the corresponding Au(I) species (NHC)AuCl are oxidized with inexpensive aqua regia. The oxidation is in some cases accompanied by substitution and/or anti addition of Cl2 across the backbone C=C bond of unsaturated NHC ligands.