Reaction and subsequent transformation of anionic acetylide-carbene complexes using the Ph3PAu+ fragment

The metallated Fischer-type carbene complexes (CO)(5)M=C(NMe(2))Ctriple bond]CLi (M = Cr, W) react with Ph(3)PAuNO(3) to form the beta-substituted products (CO)(5)M=C(NMe(2))Ctriple bond]CAuPPh(3). In solution these products isomerise by formal metal fragment exchange to furnish Ph(3)PAuC(=NMe(2))Ctriple bond]CM(CO)(5). A preliminary kinetic investigation by means of (1)H-NMR spectroscopy indicates an unusual and complicated reaction mechanism. Model DFT calculations predict small energy differences between the products before and after the metal fragment exchange.