The Synthesis And Application Of Chiral Phosphine Ligand SEGPHOS

In the dissertation, the research background, history and current situation of chiral phosphorus ligands was briefly reviewed fristly. Then the synthesis of SEGPHOS method was improved, and chiral catalyst (S-SEGPHOS)-Ru was synthesized and applied in the asymmetric hydrogenation methyl 4-chloroacetoacetate, the conversion is 100% and ee value is 96.38%. The main work as follows:1.4-bromo-1,2-(methylenedioxy)benzene is synthesized by bromination of (methylene dioxy)benzene, the yield is 90%. And the method of analysis of purity by HPLC was established.2. A Grignard reagent obtained by reaction of Magnesium and 4-Bromo-1,2-(methylenedioxy)benzene react with diphenylphosphinyl chloride to obtain diphenyl (3,4-methylenedioxyphenyl)phosphine oxide. which is purified to 96% by crystilization and the yield is 71.8%.3. (±)-((5,6),(5’,6’)-bis(methylenedioxy)biphenyl-2,2’-diyl)bis(diphenylphosphine oxide) (which will herein after be abbreviated as SEGPHOSO2) was synthesized in the one-pot oxidation-coupled diphenyl(3,4-methylenedioxyphenyl)phosphine oxide with anhydrous FeCl3. The reaction condition which influence of yield such as temperature,time, solvent and light were studied. The best condition was obtained.4. R-SEGPHOSO2 and S-SEGPHOSO2 is obtained by resolution with (+)-DBTA or (-)-DBTA. The method of determined optically purity of the compounds with HPLC was established, and both compounds optically purity ee value was measured to be over 99%.5. The chiral bidentate phosphine ligand R-SEGPHOS and S-SEGPHOS is prepared by reduction R-SEGPHOSO2 and S-SEGPHOSO2 with HSiCl3.The structures of the target compounds were characterized by 1H NMP,31P NMR.6. The chiral catalysts (R-SEGPHOS)-Ru was prepared by using R-SEGPHOS as ligands and applied in asymmetric hydrogenation methyl 4-chloroacetoacetate in good result.