PHOSPHINOALKYLNITRILES - SYNTHESIS AND COORDINATION BEHAVIOR AT PALLADIUM CENTERS

Phosphinoalkylnitriles R(2)P-(CH2)(n)-CN {R=isopropyl ((i)pr), phenyl (ph), cyclohexy ((c)hex), n=3, 6, 10} have been prepared starting from the corresponding secondary phosphines in an easy three step synthesi s. All new compounds were characterized by their H-1-, C-13 and P-31 N MR data. Some of these new P, N ligands were used to prepared complexe s [{R(2)P-(CH2)(n)-CN}2PdCl2] which were also identified by their NMR data. In addition the crystal structures of three derivatives, [{(i)pr (2)P-(CH2)(3)-CN}2PdCl2] 7a, [{ph(2)P-(CH2)(3)-CN}2PdCl2]7b and [{ph(2 )P-(CH2)(6)-CN}2PdCl2] 8b were determined by X-ray analysis. The coord ination mode of the phosphinoalkylnitriles in these complexes was foun d to be P-bonded resulting in a trans configuration. Palladium catalys ts with 5a as ligand show high activiies in the co-oligomerization of butaiene and carbon dioxide. The delta-lactone 11a is formed under ver y mild conditions.