| 噁唑硼烷催化还原二苯基已二酮的反应机理研究 |
| |
| 引用本文： | 林雪飞,孙成科,杨思娅. 噁唑硼烷催化还原二苯基已二酮的反应机理研究[J]. 曲靖师范学院学报, 2002, 0(3) |
| |
| 作者姓名： | 林雪飞 孙成科 杨思娅 |
| |
| 作者单位： | 曲靖师范学院化学系 云南曲靖655000(林雪飞，孙成科)，曲靖师范学院化学系 云南曲靖655000(杨思娅) |
| |
| 基金项目： | 云南省教委科研基金资助项目 (0 12 2 4)，曲靖师院科研基金资助项目 (2 0 0 0 0 9) |
| |
| 摘 要： | 本文用量子化学AM1方法研究了二苯基已二酮在唑硼烷催化还原下的对映体选择性反应机理 ,结果表明 ,在此硼催化剂的作用下 ,二苯基已二酮的还原对映体产物主要是R构型 ,其主要原因是两种对映体的催化过渡态的活化能相差较大所致 .用过渡态活化理论计算所得光学产率 %e .e .=99.7,研究结果与实验测定一致
|
| 关 键 词： | 二苯基已二酮 硼催化 对映体选择性 AM1 |
Theoretical Study on Reaction Mechanism in Oxazaborolidine-Catalyzed Reductions of Diphenyl Diketohexane |
| |
| LIN Xue-fei SUN Cheng-ke YANG Si-ya. Theoretical Study on Reaction Mechanism in Oxazaborolidine-Catalyzed Reductions of Diphenyl Diketohexane[J]. Journal of Qujing Normal College, 2002, 0(3) |
| |
| Authors: | LIN Xue-fei SUN Cheng-ke YANG Si-ya |
| |
| Abstract: | The reaction mechanism of the enantioselectivity in oxazaborolidine-catalyzed reductions of diphenyl diketohexane has been studied with the molecular orbital AM1 method and transition state theory.The results show that the boron-catalyzed reactions consist of two similar parallel reactions in which the reactants(R) of the title compound and boron-catalyst generate the enantiomers(P R and Ps)via intermendiate compounds IC(R) and IC(S) and transition states TS R and TS s respectively.The enantioselectivity is determined by the ratio of the rate constants of two reactions.The value is 615(that is R:S=99 85:0 15 or ?(R)=99 7),that is in good consistence with experiment [exp.?(R)=99].The determining factors of the rate ratio come from the joint contribution of the activation entyalpy and activation entropy. |
| |
| Keywords: | dipheny diketohexane boron-catalyzed enantioselectivity AM1 |
| 本文献已被 CNKI 等数据库收录！ |
