Synthesis Of Chiral Diphosphine And Their Applications In Asymmetric Hydrogenation Of Ketophosphonates And Pyridyl Ketones

In this dissertation, some C₂axial chiral bidentate phosphine ligands-SunPhos,and three chiral diamine ligands were synthesized. When the ligands were applied tothe asymmetric hydrogenation of ketophosphonates and pyridyl ketones, excellentcatalytic efficiency and stereoselectivities were obtained.The dissertation includes:1. SunPhos series ligands were synthesized by: lithiation of the ethyl phosphatewith LDA; oxidation coupling with FeCl₃; reaction of the diphosphate with SOCl₂;Grignard reaction; optical resolution with （-）-DBTA or （-）-DTTA as resolving agent;and finally reduction with HSiCl₃. The absolute configuration of the ligands wasdetermined by the means of single crystal X-ray diffraction of the salts of thediphosphine oxides with （-）-DBTA or （-）-DTTA. Three chiral diamine ligands weresynthesized （Daipen, Dm-Daipen, IPBAN）.2. Asymmetric hydrogenation of β-ketophosphonates with SunPhos ligands. It isof great significance that β-ketophosphonates were hydrogenated by ligands ofdifferent steric and electronic factors. Under the optimized reaction conditions, avariety of β-hydroxyphosphonates have been prepared with ee up to99.9%.3. Asymmetric hydrogenation of α-amido-β-keto phosphonates with SunPhosligands. In the presence of catalytic amounts of CeCl₃·7H₂O,[RuCl（benzene）（S）-SunPhos]Cl is found to be the highly effective catalyst for theasymmetric hydrogenation of α-amido-β-keto phosphonates. A variety ofβ-hydroxy-α-amido phosphonates have been prepared in high diastereo-andenantioselectivities （up to99:1dr,99.9%ee）. The reaction intermediate was proposedto be the coordination complexes of the CeCl₃·7H₂O/substrate/catalyst.4. Asymmetric hydrogenation of pyridyl ketones with Ruthenium and SunPhosligands. The reaction conditions of solvent, pressure, and temperature were optimized.RuCl₂[（S）-XylSunPhos][（S）-Daipen] was found to be the highly effective catalyst forthe asymmetric hydrogenation of pyridyl ketones. A variety of aryl-pyridyl ketones, including those with ortho substituents were hydrogenated with highenantioselectivities （ee up to99.6%）. The results are superior to Noyori’s catalyticsystem, in which good results were obtained only with added isopropyl borate.