Organopalladium(II) Complexes Containing Carbon-Bonded Heterocycles as a Ligand

Article abstract of DOI:10.1246/bcsj.59.2141

Oxidative addition reactions of 2-chloropyridine, 2,6-dichloropyridine, 2-chloropyrazine, and 2-chlorobenzothiazole with tetrakis(triphenylphosphino)palladium(0) gave <2> or trans-depending on the nature of the carbon-bonded heterocycles R.They are all stable and the chloride ligand is readily replaced by other halides and pseudohalides.These novel organopalladium(II) complexes were characterized by the analytical and molecular-weight data together with IR, 1H NMR and 13C NMR spectra, and the 2-pyridyl-bridged dinuclear structure of <2)(PPh3)>2> was previously revealed by X-ray analysis.Both of the dinuclear and mononuclear 6-chloro-2-pyridylpalladium(II) complexes catalyze the cross coupling reaction between 2,6 dichloropyridine and methylmagnesium bromide to afford 2-methyl-6-chloropyridine selectively.The mononuclear 6-chloro-2-pyridylpalladium(II) complexes react with carbon monoxide to form the acyl complexes.