https://doi.org/10.1351/goldbook.P04566
Compounds in which one or more of the OH groups of phosphoric acid have been replaced with an amino or substituted amino group; commonly confined to the phosphoric triamides, P(=O)(NR2)3, since replacement of one or two OH groups produces phosphoramidic acids P(=O)(OH)(NR2)2, P(=O)(OH)2(NR2).
Source:
PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1358 [Terms] [Paper]