Activating Water: Important Effects of Non-leaving Groups on the Hydrolysis of Phosphate Triesters
作者:Anthony J. Kirby、Michelle Medeiros、Pedro S. M. Oliveira、Elisa S. Orth、Tiago A. S. Brandão、Eduardo H. Wanderlind、Almahdi Amer、Nicholas H. Williams、Faruk Nome
DOI:10.1002/chem.201101926
日期:2011.12.23
spontaneous hydrolysis of tris‐2‐pyridyl phosphate (TPP) is explained by the activating effects of the non‐leaving (“spectator”) groups on POAr cleavage, and not by intramolecular catalysis. Previous work on phosphate‐transfer reactions has concentrated on the contributions to reactivity of the nucleophile and the leaving group, but our results make clear that the effects of the non‐leaving groups on phosphorus
三-2-吡啶基磷酸酯的自发水解的高速率(TPP)是通过在P上的非离开(“旁观者”)基团的激活作用说明OAr裂解,而不是通过分子内催化。先前有关磷酸盐转移反应的研究主要集中在亲核试剂和离去基团对反应活性的贡献上,但我们的结果表明,非离去基团对磷的影响同样重要。对三个系列的磷酸三酯的速率测量结果表明,对于自发水解反应,对非离去基团的敏感性非常重要,尽管对于具有良好亲核试剂的反应,其敏感性要小得多。有在离开和非离去基团与示出了用于两个较低值的更具反应性的三芳基系统之间的三芳基和二烷基芳基三酯在灵敏度明显的差异β LG和β NLG。相邻的吡啶氮原子对TPP水解的分子内催化作用微不足道,主要是因为它们的碱度低。