Silylpalladium Cations Enable the Cleavage of Nitrile C–CN Bonds

The stoichiometric addition of aryl and alkyl nitriles to the silylpalladium cation (PCy3)2Pd–SiMe2Et+(C6F5)4B– (1) resulted in the cleavage of the nitrile C–CN bond and the formation of palladium–aryl and palladium–alkyl cations. Low-temperature experiments support a mechanism where silylpalladium cation 1 transfers silylium to nitrile, generating a silylnitrilium cation and the reduced, zerovalent complex Pd(PCy3)2. These two intermediates readily recombine at low temperatures to generate palladium–(N-silyl)iminoacyl complexes, which upon warming can undergo aryl/alkyl group migration from the iminoacyl ligand to the metal. Additional experiments show that palladium–(N-silyl)iminoacyl cations are potent sources of silylium, capable of cleaving the methyl C–O bond of an ether, while DFT calculations confirm the electrophilicity of the silyl moiety.