Phosphorimidates and related compounds

Abstract

Phosphorimidates and related compounds (R¹R²R³P:NR⁴) have been prepared by Staudinger reactions between three-co-ordinate phosphorus nucleophiles and azides. I.r., mass, and n.m.r. spectral studies on the compounds are reported. Low-temperature ¹H n.m.r. studies suggest that the rotational barrier around the P:N bond in these compounds is below 8 kcal mol^–1. Thermal rearrangements of some methyl phosphorimidates to phosphoramidates [P (OMe):NMe → FP(:O)NMe₂] have been observed.