Intramolecular Hydrogen-Bond Participation in Phosphonylammonium Salt Formation

A series of phosphonochloridates and phosphonyl dichlorides were prepared, and their reactivity with triethylamine has been investigated using ³¹P NMR spectroscopy. Taken together these studies provide evidence that an intramolecular hydrogen-bond is required for phosphonylammonium salt formation to render the phosphorus more electron-deficient.