The phosphorus–nitrogen bond. Synthesis, characterization, and infrared studies of heterocyclic phosphoryl (phosphetan) amides

Abstract

Several new amide derivatives of the heterocyclic 2,2,3,4,4-pentamethylphosphetan 1-oxide (1) have been prepared by heating together the corresponding chloride and amine at elevated temperatures. The products have been characterized by ¹H and ¹³P n.m.r. spectroscopy and in particular by i.r. spectroscopy over the range 400–4000cm^–1. In one case a mass spectrum is reported in detail. Evidence for hindered rotation about the P–N bond is discussed and interpreted in terms of pπ–dπ contributions to the bonding.