Two new chiral phosphine ligands,1,4∶3,6-dianhydro-2,5-O-dideoxy-2,5-bis(dipheny-phosphinoxy)-L-iditol and 1,4∶3,6-dianhydro-2,5-O-dideoxy-2,5-bis(dipheny-phosphinsulphur)-L-iditol were prepared from D-mannitol.Palladium catalytic systems formed with these ligands in situ were used as asymmetric homogenous catalysts for hydroesterification of styrene,giving(R)-2-phenyl propionate in 16.9 and 9.2% ee values,respectively.
