New Pd-NHC PEPPSI complexes from benzimidazolium salts with a phenacyl group attached to N3

Abstract

New benzimidazole-2-ylidene palladium(II) complexes of PEPPSI type, having pyridine as a throw-away ligand were obtained in one step from phenacyl benzimidazolium bromides and PdCl2. Although the presence of phenacyl groups attached to the N3 could lead in basic medium either to the N-heterocyclic carbenes or to the corresponding N-ylides, 6 new complexes were obtained without need of supplementary reactions steps or carbene transfer agents. X-ray diffraction analysis revealed that the expected chlorine atoms in the complexes were replaced by bromine atoms.