Microwave-Assisted Functionalization of Phosphinic Acids: Amidations versus Esterifications
作者:György Keglevich、Nóra Zsuzsa Kiss、Tamás Körtvélyesi
DOI:10.1002/hc.21068
日期:2013.3
calculations were against the direct amidation of phosphinic acids under traditional thermal conditions. However, the amidations, not expected to proceed on the basis of the endothermicity and the significantly high enthalpies of activation, did take place under microwave (MW) conditions in 30–36% conversions. As a comparison, the direct esterifications of phosphinic acids that are thermoneutral and have
通过高水平量子化学计算得到的反应焓和活化焓都反对次膦酸在传统热条件下的直接酰胺化。然而,基于吸热性和显着高活化焓预计不会进行酰胺化,确实在微波 (MW) 条件下以 30-36% 的转化率发生。相比之下,热中性且具有较高活化焓的次膦酸的直接酯化在 MW 条件下非常有效。MW 辅助酰胺化的结果是两种效应的平衡。局部过热效应可以克服活化焓所意味着的障碍,但吸热性与此相反。比较合成结果和为次膦酸的酯化和酰胺化计算的能量学,使我们能够对有机合成中使用 MW 辐射的范围和限制得出更一般的结论。通过次膦酰氯中间体进行次膦酸的传统酰胺化得到了更高产率的产物。© 2013 Wiley Periodicals, Inc. 杂原子化学 24:91–99, 2013; 在 wileyonlinelibrary.com 上在线查看这篇文章。DOI 10.1002/hc.21068 杂原子化学 24:91–99, 2013;