Synthesis, characterization and catalytic application of secondary carbene palladium(II) complexes obtained by oxidative addition reaction

Three new secondary carbene palladium(II) complexes (1b–3b) were synthesized via oxidative insertion of Pd2(dba)3 (dba = dibenzylideneacetone) into the C–Cl bond of dialkyl(chloromethylene)ammonium chloride salts ([R2NCHCl]+Cl−). All complexes have been characterized by 1H, 13C, and 31P NMR analysis. X-ray diffraction studies on single crystal of 3b confirm the cis square planar geometry. Complexes (1b–3b) have been proved to be efficient catalysts in the Heck coupling of styrene with 4-bromoacetophenone.