Some new oxazaborolidines 1~5, Prepared from the reaction of (1R, 2S)-epherdrine and BH3.SMe2 or RB(OH)2, Serve as chiral catalysts for the asymmetric reduction of acetophenone with borane to give the (R)-1-phenylethanol with 38.5~72.4% e.e. in high yield. The structure- reaction relationship of the catalysts and the effect of reaction parameters (the amount of catalyst and reaction temperature) on enantioselectivity of the reduction are discussed.

Key words: CATALYSIS, ACETOPHENONE, BORANE, BORON HETEROCYCLIC COMPOUNDS, EPHEDRINE, PHENYLETHANOL, REDUCTION REACTION