Homogeneous asymmetric catalysis by means of chiral metal complexes of 2,3-bis(dimenthylphosphino)maleic anhydride and of 2,3-bis(dimenthylphosphino)maleimide derivatives

Article abstract of DOI:10.1016/0022-328X(89)87298-5

2,3-bis(dimenthylphosphino)maleic anhydride and also 2,3-bis(dimenthylphosphino)maleimide derivatives have been prepared from 2,3-dichloromaleic anhydride, 2,3-dichloro-N-phenylmaleimide and 2,3-dichloro-N-methylmaleimide, respectively, and dimenthyl(trimethylsilyl)phosphine.These compounds have been used as ligands for Rh complexes in the asymmetric hydrogenation and hydrosilylation.Ni and Pd complexes of these ligands were tested in the Grignard cross-coupling reaction.The hydrogenation of α-acetamido cinnamic acid gave 70percent enantiomeric excess (ee) and hydrogenation of acetophenone up to 47percent ee.Hydrosilylation of acetophenone led to 42percent ee.Attempts to asymmetric cross-coupling reactions resulted in very low enantiomeric excess.