have been prepared by various synthetic methods. Rhodium(I) complexes of 3 and 8 showed high catalytic activity for hydrogenation of various kinds of prochiral ketones, which were reduced smoothly to the corresponding optically active hydroxy compounds, under hydrogen at atmospheric pressure and ambient temperature. The neutral rhodium(I) complexes (diphosphine-RhN) hydrogenated α-ketoamides and α-ketopantolactone
Tetraalkyl analogs of DIOP, (−)-EtDIOP, (−)-i-PrDIOP, and (−)-CyDIOP, have been prepared for the first time by the reaction of (+)-2,3-O-isopropylidene-2, 3-dihydroxy-1,4-difluorobutane and the corresponding lithium dialkylphosphides. These diphosphines form cationic Rh(I) complexes, [Rh(-)-RDIOP} (NBD)]C104 (R=Et, i-Pr, and Cy), which show remarkable reactivity toward dihydrogen