摘要
A heterogeneous chiral catalyst Fe(III)-CS(chitosan)complex/mesoporous molecular sieve SBA-15(Santa Barbara Amorphous)was prepared.The asymmetric transfer hydrogenations of prochiral acetophenone and 4-methyl-2-pentanone to corresponding chiral alcohols were carried out on Fe-CS/SBA-15 at atmosphere pressure using 2-propanol as hydrogen donor.Effects of Fe content in cata-lyst,reaction temperature,reaction time and promoter KOH concentration on the conversion of substrates and enantio-selectivity were investigated.Fe-CS/SBA-15 with 2.2%mass fraction Fe exhibits considerable enantioselectivity and cata-lytic activity for the asymmetric transfer hydrogenations of aromatic ketone and aliphatic ketone.Under optimal reaction conditions:KOH concentration 0.03 mol/L,reaction tem-perature 70℃ and reaction time 4 h,enantiomer excess(ee)of(R)-1-phenylethanol and conversion of acetophenone can reach 87.4%and 27.7%,respectively.Under the above KOH concentration and reaction temperature and reaction time of 8 h,the ee of(R)-4-methyl-2-pentanol and conversion 4-methyl-2-pentanone amounted to 50.2%and 25.5%,respectively.
基金
supported by the State Key Program of Fundamental Research(Grant No.2004CCA05900)
the National Natural Science Foundation of China(Grant No.50662004).
