The reactivity of phosphate esters. Reactions of diesters with nucleophiles

Abstract

The reactions of a wide range of nucleophiles with a series of aryl methyl phosphate ester anions involve concerted nucleophilic displacement at phosphorus. The attack of neutral nucleophiles is slower than the corresponding reactions of both triesters and monoester monoanions. S_N2(P) reactions involving the attack of anions on phosphate diester anions are observed, and are shown to be retarded by a factor of ca. 100 times in rate, which is ascribed to an adverse electrostatic effect. Sensitivities to both nucleophile and leaving group are considerable, and show some dependence on reactivity: they are also apparently affected by the electrostatic effect.