Synthesis and characterization of palladium(II) complexes with 2-(2 '-pyridyl)quinoline. Catalytic air oxidation of olefins by palladium(II) complexes

摘要

Palladium(II) complexes of 2-(2'-pyridyl)quinoline (PQ), namely [PdX2(PQ)] (X=Br-, I-, N-3(-), NO2-, SCN-, acac) and [PdCl(NO3)(PQ)] have been synthesized via substitution reactions of [PdCl2(PQ)] with an excess of sodium salts and acetylacetone. The complexes have been characterized by elemental analysis, conductivity measurements, IR, H-1 and C-13 NMR spectroscopy. Selected complexes have been further characterized using electrospray ionization (EST) and ion trap mass spectroscopy (ITMS). Some complexes are found to catalyze the rapid air oxidation of alpha-olefins under Wacker oxidation. The chlorohydrin products are produced in good to excellent yields while oxidation products are obtained in low yields. The [PdCl2(PQ)] complex is found to have the highest catalytic activity.