Reactions of phosphonic acid esters with nucleophiles. Part IV. Hydrazines and hydroxylamines with p-nitrophenyl methylphosphonate

Abstract

A steric argument accounts for the orders of reactivity of two parallel series of hydrazines and hydroxylamines with p-nitrophenyl methylphosphonates. The α effect is not especially important. The unusually high reactivity of hydroxylamine may reflect O-attack for this species. In some cases hydrogen bonding to the phosphoryl oxygen atom in the transition state is a possibility. The results agree with prevailing theories on the forces which control nucleophilic substitution at a tetrahedral phosphorus atom.