A Study on the Direct Esterification of Monoalkylphosphates and Dialkylphosphates; The Conversion of the Latter Species to Trialkylphosphates by Alkylating Esterification
作者:Péter Ábrányi-Balogh、Nikoletta Harsági、László Drahos、György Keglevich
DOI:10.3390/molecules27154674
日期:——
not be promoted by MWs. Hence, dialkylphosphates had to be converted to triesters by another method that was alkylation. In this way, it was also possible to synthesize triesters with different alkyl groups. Eventually a green, P-chloride free MW-promoted two-step method was elaborated for the synthesis of phosphate triesters.
某些对酸的微波 (MW) 辅助直接酯化是一种绿色方法。量子化学计算表明,放热的磷酸单烷基酯 → 磷酸二烷基酯转化的活化焓 (Δ H # ) 平均为 156.6 kJ mol -1,而磷酸二烷基酯 → 磷酸三烷基酯转化的活化焓 (Δ H # )稍高,为 171.2 kJ mol -1,并且该酯化的元素步骤的能量学不太有利。直接单酯化可以在合适的离子液体添加剂存在下对MW辐照进行。然而,第二步,整体上不太有利的能量学,不能由MW推动。因此,必须通过另一种烷基化方法将磷酸二烷基酯转化为三酯。这样,也可以合成具有不同烷基的三酯。最终阐述了一种绿色、无 P-氯化物 MW 促进的两步法合成磷酸三酯。