Phosphorylation of Diaminopyridines: Synthesis of a Compound Containing Both a Diphosphinoamine (P–N–P) and an Iminobiphosphine (N=P–P) Fragment

Abstract

AbstractThe phosphorylation of a series of diaminopyridines (2,3‐, 3,4‐, 2,5‐ and 2,6‐diaminopyridine), with various molecular equivalents of chlorodiphenylphosphine in the presence of TEA has been studied. Notably, phosphorylation of 2,3‐ and 3,4‐diaminopyridine affords compounds with diphosphinoamine (P–N–P) and iminobiphosphine (N=P–P) entities co‐existing in the same molecule. Phosphorylations of 2,5‐ and 2,6‐diaminopyridine afford compounds containing only diphosphinoamine units. The solid‐state structure of three compounds has been determined including the first example of a crystallographically characterized compound containing both a diphosphinoamine group and an iminobiphosphine group in the same structure.