无痕施陶丁格连接反应机理的理论研究

叠氮化合物和膦硫酯的无痕施陶丁格连接反应是一种有效生成酰胺键的方法. 通过密度泛函方法研究了无痕施陶丁格连接的反应机理. 计算结果表明反应的决速步为反应的第一步, 即膦进攻叠氮的端基氮, 形成膦基叠氮化物的过程. 膦亚胺中间体形成之后, 向不同方向转化(酰基迁移后水解或者直接水解)的难易程度决定了最终产物的组成. 对几种不同偶联试剂介导的无痕施陶丁格连接反应的计算结果, 都与实验数据相吻合.

Theoretical Study on Reaction Mechanism of Traceless Staudinger Ligation

The traceless Staudinger ligation of azides and phosphines is an effective method to produce an amide bond. In this work, density functional theory (DFT) calculations were carried out to investigate the mechanism of the traceless Staudinger ligation, which suggested that its rate-limiting step was the attack of azide on phosphine leading to the formation of phosphazide. After the formation of iminophosphorane intermediate, competition between acyl transfer followed by hydrolysis and direct hydrolysis determined different product distributions. The traceless Staudinger ligations mediated by different coupling reagents were then computed. The results were consistent with the experiments.