(R,S)-BINAPHOS-Ni(0) and -Pd(0) complexes: Characterization and use for asymmetric hydrocyanation of norbornene

Zerovalent nickel and palladium complexes bearing phosphine-phosphite ligand, (R,S)-BINAPHOS, have been prepared. The complexes M(binaphos)(2) (M=Ni, Pd) were characterized on the basis of P-31 NMR spectroscopy and FAB mass spectroscopy. These complexes have been applied to asymmetric hydrocyanation of norbornene, giving the corresponding exo-nitrile, Enantioselectivities up to 48% ee have been obtained with the palladium complex as catalyst. This is the highest ee ever reported using norbornene as a substrate, Nickel catalyst was more active but less enantioselective (up to 40% ee). The palladium-catalyzed reaction was greatly inhibited by adding excess ligand. (C) 1997 Published by Elsevier Science Ltd.