Asymmetric catalysis

Claim 1

An asymmetric hydrogenation process affording an optical purity of enantiomorph of at least about 86 percent comprising hydrogenating a compound of the formula ##STR11## wherein R, R 1 and R 2 each independently represent hydrogen, substituted or unsubstituted alkyl having from 1 to 5 carbon atoms or substituted or unsubstituted aryl, and R 3 represents substituted or unsubstituted alkyl having from 1 to 5 carbon atoms or substituted or unsubstituted aryl, provided that, if only one of R and R 1 is hydrogen the Z geometric isomer is hydrogenated, in the presence of from about 0.001% to about 5% by weight, based on said compound, of a homogeneous, coordination complex of rhodium, iridium or ruthenium in combination with an optically active bis phosphine ligand represented by the formula ##STR12## wherein A and B each independently represent substituted or unsubstituted alkyl of from 1 to 12 carbon atoms, substituted or unsubstituted cyclo alkyl having from 4 to 7 carbon atoms, or substituted or unsubstituted aryl; provided that such substituents provide no significant interference with the steric requirements around the phosphorus atom and A and B are different, said process being conducted at a temperature of from about -20° C. to about 110° C. and said hydrogen concentration being equal to about 0.5 to about 5 times the mole quantity of said compound.