Synthesis Of H₄-BINOL And Its Derivatives And Their Application In Asymmetric Hydrosilylation

The synthesis and application of partially saturated H4-BINOL, H8-BINOL were reviewed in the dissertation. The new method of synthesis of H4-BINOL was developed in order to overcome the drawback of the reported references. (S)-H4-BINOL was synthesized up to 83% total yield via hydrogenation of non-symmetric monoester of (S)-BINOL with optimal conditions:(4.7mol%) 5% Pd/C,50 atm H2,4 h and EtOH as solvent. The two isomers (S)-2b (47% yield) and (S)-3b (36% yield) were isolated with column chromatography.Although the three-step reaction could offer H4-BINOL in good yield. The process is somewhat inconveniently, and the multi-step reaction is not atom economy. After finished the above reaction, we tried to synthesis of H4-BINOL by directly hydrogenation of BINOL. The hydrogenation was carried out under different conditions (temperature, pressure, solvent, catalyst and reaction time). The best yield (up to 78%) was obtained with optimum condition:5% Pd/C (4.7 mol%) in EtOH under the H2 pressure of 50 atm for 2 h.With the two isomers (S)-2b and (S)-3b in hand, we synthesized a series of analogue H4-MOP and H'4-MOP (14a-14d,15) of the MOP in order to test the activity in the palladium catalytic asymmetric hydrosilylation reaction. All the ligands showed high catalytic activity,67-93% yield were provided in the hydrosilylation of styrene, but the effectiveness of the chiral induce was modest, the enantiomeric excess 2-26% were obtained. The ligands 14d with two bistrifluoromethylphenyl gave the best ee value among the ligands (26% ee). Several styrene derivatives were runed in the hydrosilylation with 14d as ligands. The best result was obtained with p-methoxystyrene as substrate, the yield (91%) and enantiomeric excess (58%) was obtained, respectivesly.