Palladium Complexes of a P2C Ligand Containing a Central Carbene Moiety

Palladium(II) complexes of the PCHP pincer ligand were prepared from PdCl2, a “proto-pincer” P2CH2, and base. The resulting (PCHP)PdCl was converted to (PCHP)PdOTf. (PCHP)PdCl did not react with NaN(SiMe3)2 but produced (PCHP)PdR (R = Me, Et, Ph) upon reaction with the corresponding organolithium, Grignard, or organozinc reagent. Trityl cation abstracted a hydride from (PCHP)PdCl to yield cationic Pd carbene complex (P2C)PdCl. Analysis of the structural data points to minimal π-interaction between the carbene center and palladium.