Metal-ligand cooperation between palladium and a diphosphine ligand with an olefinic backbone

The tridentate palladium(0) compound [(cPCMeCMeP)Pd] ((Z)-2,3-bis(2-di-iso-propylphosphinephenyl)-2-butene) was synthesized and its oxidative addition products with CH3I, C6H5I, Ph2SiH2, and HCl were characterized. Hemilability of the olefinic backbone is observed in all cases and, excluding Ph2SiH2, results in trans palladium(II) species. Oxidative addition of Ph2SiH2 results in a fluxional species due to the reversibility of the SiH bond activation. Reactivity with HCl led to the oxidative addition of the acid, resulting in the formation of a clorohydride complex, [(cPCMeCMeP)PdHCl], followed by a irreversible insertion of the olefin into the PdH bond resulting in [(PCMeCHMeP)PdCl]. Additionally, dehydrohalogenation was achieved with [(cPCMeCMeP)PdCl2] resulting in [(PCMeC(CH2)P)PdCl]. All metal complexes were characterized by multi-nuclei NMR spectroscopy, X-ray crystallography, and elemental analysis.