Patent ID: 7414156

Claim:
A non-C 2 symmetric bisphosphine ligand having structural formula: wherein the bridge is a 1,2-divalent phenyl, a 1,2-divalent substituted phenyl, or a —(CH 2 ) n — in which n is an integer from 1 to 12; the achiral phosphine group is in which R is t-butyl, isopropyl, adamantyl, 1,1-dimethyipropane, 1,1-diethylbutane, c-C 5 H 9 , or c-C 6 H 11 ; and the chiral phosphine group includes a three-coordinated phosphorous atom which is bonded to the bridge and to two carbon atoms, the phosphorus atom and the two carbon atoms being part of a ring system containing only phosphorus and carbon atoms as ring members.