Abstract: Chiral secondary alcohol is the important organic synthesis intermediates of many drugs, pesticides and functional materials and so on. Catalytic reduction of prochiral ketone is one of the important ways to acquire chiral secondary alcohols high enantiomeric excess percentage (e.e. value) by chiral amino alcohols ligand.Chiral alcohol has become one of the most active research areas in recent years. This paper summarizes the new progress of the asymmetric catalytic reduction reaction on the basis of relevant references.
In order to find high-powered catalyst remains and achieve available chiral secondary alcohols higher e.e. value, on the basis of collaborative effects of multiple catalysis center ligand in asymmetric catalytic reduction of synergies, we had used (1S,2R)-(+) and (1R,2S)-(-) -2-amino-1,2-diphenyl ethanol as chiral sources with 1,3-benzyl bromide reaction respectively. By optimizing the reaction conditions in ethanol solution at 70 ℃, KI as a catalyst and K2CO3 as a hydrogen absorption reagent first synthesized the catalysis center with two ligand, N-(1R,2S)-(1,2-diphenyl-2-hydroxyl) ethyl-1,3-benzyl amine and N-(1S,2R)-(1ˊ,2- diphe nyl-2ˊ-hydroxyl) ethyl-1,3-benzyl amine, getting the colorless crystal by silica gel column chromatographyl, and yields were 80.3% and 78.8% respectively. Products have been confirmed by IR and 1HNMR, etc. Among pairs of enantiomers in synthesis, their action spectrum character, the melting point and specific rotation etc. other physical constants are well proofed.
Key words:Chiral Amino Alcohols; Ligand; Synthesis;Purify
