对氯苯基乙酮不对称还原反应的理论研究

基于AM1分子轨道法计算 ,从热力学和动力学两方面研究了两种手性唑硼烷催化对氯苯基乙酮的不对称还原反应 ,获得了CBS四步反应机理中各步的反应热以及第II步的反应活化能 .结果表明 ,第II步和第IV步是吸热过程 ,采用唑硼烷的PhO基衍生物作催化剂有利于提高该不对称还原反应的对映选择性 .理论预测的产物手性及光学活性 (ee值 )与实验结果相吻合

Theoretical Study on the Enantioselective Reduction of p-Chlorophenyl Ethyl Ketone

Theoretical study on the enantioselective reductions of p chlorophenyl ethyl ketone catalyzed by two chiral oxazaborolidines has been performed by AM1 MO method. The reaction includes four steps. The heat of reaction of each step and the activation energy of the 2nd step were obtained. It was found that the 2nd step and the 4th step are endothermic. Meanwhile, computations showed that the enantioselectivity of the reduction increased by using the PhO derivative of chiral oxazaborolidine as catalyst. The predicted chirality and optical activity of the final product are in agreement with the experimental result.