Intramolecular general acid catalysis of intramolecular nucleophilic catalysis of the hydrolysis of a phosphate diester

Abstract

The dianion (8) of bis-2-carboxyphenyl phosphate (half-life 10.2 min at 39 °C) is hydrolysed ca. 10¹⁰ times faster than diphenyl phosphate. The reaction is accounted for in terms of intramolecular general acid catalysis by the ortho-CO₂H of one salicyl group of the breakdown of the penta-covalent intermediate formed by the addition to phosphorus of the carboxylate group of the other. The general acid catalysis part of the process is unexpectedly inefficient.