Mechanism of hydrolysis of phosphorylethanolamine diesters. Intramolecular nucleophilic amine participation
1980; Royal Society of Chemistry; Issue: 2 Linguagem: Inglês
10.1039/p29800000373
ISSN2050-8239
AutoresRobert A. Lazarus, Patricia A. Benkovic, Stephen J. Benkovic,
Tópico(s)Organic and Inorganic Chemical Reactions
ResumoIntramolecular displacement reactions at phosphorus have been examined in a series of N-alkyl-O-arylphosphorylethanolamines in water at 35 °C. The examination of the pH–rate profiles and the direct observation by 31P n.m.r. of the reaction products implicate a nucleophilic role for the amine. A rate enhancement of 106–107 is observed. Structure–reactivity correlations derived by changing the pKa of the amine and leaving group yield values for βnuc≃ 0.7 and β1g≃–1.25 and support an uncoupled concerted mechanism. A discussion of the mechanisms of nucleophilic reactions involving amines and oxyanions with inter- and intra-molecular phosphate di- and tri-esters is presented.
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