Methanolysis of phosphate triesters

La ( 0CH3))2 Catalysis of the Methanolysis of Phosphate Triesters Having ortho-C(=0)OCH3 Group. ... 

The apparent second-order rate constant for hydroxide ion attack on trimethyl phosphate (26) is increased 400-fold when the phosphoryl moiety is coordinated to an iridium(III) center."" Wadsworth has presented evidence that ZnClj-medi-ated methanolysis of phosphate triesters involves metal interaction with phosphoryl oxygen and the leaving-group oxygen." The divalent metal ions, Mg + and catalyze the reaction of 4-nitrophenyl phosphate dianion (28) with... 

Scheme 6 A proposed mechanism for the concerted La + ( OCH3)2-catalyzed methanolysis reaction of phosphate triesters with XAr leaving groups.

Liu T, Neverov AA, Tsang JSW, Brown RS. Mechanistic studies of La and Zn -catalyzed methanolysis of aryl phosphate and phosphorothioate triesters. Development of artificial phosphotriesterase systems. Org Biomol Chem. 2005 3 1525-1533. 

Mentz, M., Modro, A.M., Modro, T.A. Solvation and metal ion effects on the structure and reactivity of phosphoryl compounds. Part 3. Alkali metal ion catalysis in the alkylation by phosphate esters. J. ChettL Res. (S) 1994, 46-47. Hendry, P, Sargeson, A.M. Base hydrolysis of the pentaamine (trimethylphos-phate)iridium(in) ion. J. Chem. Soc., Chem. Commun. 1984, 164—165. Wadsworth, W.S., Jr. Lewis acid catalyzed methanolysis of a phosphate triester. J. Org. Chem. 1981, 46(20), 4080-4082. 

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