We have synthesized and characterized several cationic complexes of gold(I) of the type [Au(L 1 )(L 2 )] + (L 1 =NHC, L 2 =DIC; L 1 =NHC, L 2 =NAC; L 1 =NAC, L 2 =DIC; L 1 =L 2 =NAC; NHC=N-heterocyclic carbene; NAC=N-acyclic carbene, DIC=2,6-dimethylphenylisocyanide).The complexes of type [Au(NHC)(DIC)] + react with a slight excess of Br 2 yielding the corresponding gold(III) species [Au(NHC)(DIC)Br 2 ] + . The latter decompose with a rate that is modulated by the nature of the ancillary ligands. The oxidative addition of Br 2 to complexes of the type [Au(NHC)(NAC)] + and [Au(L)(NAC)] + (L=DIC, NAC) has been also carried out and the ensuing gold(III) derivatives [Au(NHC)(NAC)Br 2 ] + and [Au(NAC) 2 Br 2 ] + are stable in solution whereas the complex [Au(NAC)(DIC)Br 2 ] + decomposes. Finally, on the basis of kinetic studies we have proposed propose a mechanism involving a fast pre-equilibrium forming an adduct containing the starting complex and Br 2 followed by a slow rearrangement of the latter to yield the final gold(III) derivatives.