Phosphonate Diester and Phosphonamide Synthesis. Reaction Coordinate Analysis by <sup>31</sup>P NMR Spectroscopy: Identification of Pyrophosphonate Anhydrides and Highly Reactive Phosphonylammonium Salts<sup>1</sup>
作者:Ralph Hirschmann、Kraig M. Yager、Carol M. Taylor、Jason Witherington、Paul A. Sprengeler、Barton W. Phillips、William Moore、Amos B. Smith
DOI:10.1021/ja962465o
日期:1997.9.1
A series of phosphonochloridates was prepared from the corresponding phosphonate monoesters, and their reactions with alcohols, amines, and the bisnucleophile 4-aminobutan-1-ol have been investigated using 31P NMR spectroscopy. In the conversion of phosphonate monoesters to phosphonochloridates via the addition of thionyl chloride or oxalyl chloride, pyrophosphonate anhydrides were found to be formed
从相应的膦酸酯单酯制备了一系列膦酰氯,并使用 31 P NMR 光谱研究了它们与醇、胺和双亲核试剂 4-氨基丁-1-醇的反应。在通过加入亚硫酰氯或草酰氯将膦酸单酯转化为膦酰氯时,发现焦膦酸酐很容易作为副产物形成。酸酐很容易与醇反应,但比相应的膦酰氯反应更慢,而且与胺反应也很缓慢,如果有的话。因此,在制备膦酰胺时,必须抑制酸酐的形成。这是在将单酯添加到氯化剂中时完成的。不受阻碍的膦酰氯主要与 4-氨基丁-1-醇的氨基官能团反应以提供膦酰胺,而空间位阻的膦酰氯表现出对 O 偶联的偏好。该结果表明在 P−O b 期间获得的能量...