Computational study of the substitution effect on the mechanism for phospha-Wittig reaction
Computational study of the substitution effect on the mechanism for phospha-Wittig reaction
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DOI：
10.1007/s00214-009-0579-z
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发表时间：
2009-09-01
影响因子：
1.7
通讯作者：
Liao, Hsin-Yi
中科院分区：
文献类型：
--
作者：
Liao, Hsin-Yi
使用密度泛函理论计算检查 Phospha-Wittig 反应 HP=PH3 + O=CHX -> HP=CHX + O=PH3 (X = H、F、Cl、Me、OMe、NMe2、CMe3)。所有结构均在 B3LYP/6-311++G** 理论水平上完全优化。通过估计其活化能来检查各种 O=CHX 的反应性。这项工作的主要发现是构型混合模型可以成功预测 phospha-Wittig 反应的活化能和反应焓的相对顺序。结果表明，具有更多电释放取代基的O=CHX将具有更小的单线态-三线态分裂。这将促进磷-维蒂希反应并导致更大的放热。
The phospha-Wittig reaction HP=PH3 + O=CHX -> HP=CHX + O=PH3 (X = H, F, Cl, Me, OMe, NMe2, CMe3) was examined using the density functional theory calculations. All of the structures were completely optimized at the B3LYP/6-311++G** level of theory. The reactivities of various O=CHX were examined by estimating their activation energies. The main finding of this work is that the configuration mixing model can successfully predict the relative ordering of the activation energy and reaction enthalpies of the phospha-Wittig reaction. It was demonstrated that O=CHX with more electro-releasing substituents will possess a smaller singlet-triplet splitting. This will facilitate the phospha-Wittig reaction and will result in a larger exothermicity.