Coordination of Olefins and N-Donor Ligands at the Fragment 2,6-Bis((diphenylphosphino)methyl)pyridine- palladium(II). Synthesis, Structure, and Amination of the New Dicationic Complexes Pd(PNP)(CH2CHR)(BF4)2 (R = H, Ph)

Dicationic complexes of palladium(II) containing the tridentate ligand 2,6-bis((diphenylphosphino)methyl)pyridine (PNP) of the general formula Pd(PNP)L(BF 4 ) 2 (L = MeCN, pyridine, C 2 H 4, CH 2 CHPh) have been prepared from Pd(PNP)Cl 2 by addition of 2 equiv of AgBF 4 in the presence of an excess of the respective ligand L in CH 2 Cl 2 . The corresponding amine complex (L = NHMe 2 ) was obtained by substitution of the acetonitrile from Pd(PNP)(MeCN)(BF 4 ) 2 by NHMe 2 at 0 °C. The complexes were characterized by 1 H, 13 C, and 31 P NMR spectroscopy, and the molecular structure of the styrene complex was determined by X-ray diffraction analysis. The spectral and structural parameters of the complexes are discussed in comparison to those of the recently prepared Rh(I) analogues. Nucleophilic attack of secondary amines on the coordinated olefins gave the corresponding β-aminoethyl complexes from which, upon reductive degradation, the respective ethylamines were obtained, showing selective anti-Markovnikov addition in the case of the styrene complex.