Suggs Jack B, Melko Joshua J
Department of Chemistry and Biochemistry, University of North Florida, Jacksonville, FL 32224, USA.
Molecules. 2025 Jan 11;30(2):268. doi: 10.3390/molecules30020268.
The formation of water structures can provide significant benefits in organic reactions, stabilizing charge and lowering activation energies. Hydrolysis reactions will frequently rely on water networks to accomplish these goals. Here, we used computational chemistry and experimental kinetics to investigate a model thioester molecule S-ethyl trifluorothioacetate, and extended work on a previously characterized ester p-nitrophenyl trifluoroacetate. We found that the rate-determining steps in these reactions are heavily influenced by the nature of the leaving group. The hydrolysis of S-ethyl trifluorothioacetate was much slower than p-nitrophenyl trifluoroacetate for this reason. We explored differences in the reaction orders with respect to water and examined details of calculated potential energy surfaces of these hydrolysis reactions, highlighting the roles of solvation effects and transition state structures.
水结构的形成在有机反应中能带来显著益处，可稳定电荷并降低活化能。水解反应常常依赖水网络来实现这些目标。在此，我们运用计算化学和实验动力学来研究模型硫酯分子三氟硫代乙酸乙酯，并对先前已表征的酯对硝基苯基三氟乙酸酯展开拓展研究。我们发现这些反应中的速率决定步骤受离去基团性质的影响很大。正因如此，三氟硫代乙酸乙酯的水解比三氟乙酸对硝基苯酯要慢得多。我们探究了关于水的反应级数差异，并研究了这些水解反应计算出的势能面细节，突出了溶剂化效应和过渡态结构的作用。
