Intramolecular nucleophilic catalysis in the hydrolysis of 4-nitrophenyl quinotin-8-yl phosphate

Abstract

The hydrolysis of the title ester is shown to involve expulsion of 4-nitrophenol via intramolecular nucleophilic attack at phosphorus by the quinolinyl nitrogen. Strain in ring closure is proposed as the explanation for the less efficient action than carboxylate attack in the hydrolysis of 2-carboxyphenyl 4-nitrophenyl phosphate. The considerable mechanistic ambiguity due to the dibasic nature of the ester is resolved by comparison with appropriate models.