The Mechanism of Dephosphorylation of Bis(2,4-dinitrophenyl) Phosphate in Mixed Micelles of Cationic Surfactants and Lauryl Hydroxamic Acid

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• 作者：Marcelo Silva ; Renata S. Mello ; M. Akhyar Farrukh ; Janio Venturini ; Clifford A. Bunton ; Humberto M. S. Milagre ; Marcos N. Eberlin ; Haidi D. Fiedler ; Faruk Nome
• 刊名：Journal of Organic Chemistry
• 出版年：2009
• 出版时间：November 6, 2009
• 年：2009
• 卷：74
• 期：21
• 页码：8254-8260
• 全文大小：850K
• 年卷期：v.74,no.21(November 6, 2009)
• ISSN：1520-6904

文摘

Mixed micelles of cetyltrimethylammonium bromide (CTABr) or dodecyltrimethylammonium bromide (DTABr) and the α-nucleophile, lauryl hydroxamic acid (LHA) accelerate dephosphorylation of bis(2,4-dinitrophenyl)phosphate (BDNPP) over the pH range 4−10. With a 0.1 mole fraction of LHA in DTABr or CTABr, dephosphorylation of BDNPP is approximately 10<sup>4sup>-fold faster than its spontaneous hydrolysis, and monoanionic LHA<sup>−sup> is the reactive species. The results are consistent with a mechanism involving concurrent nucleophilic attack by hydroxamate ion (i) on the aromatic carbon, giving an intermediate that decomposes to undecylamine and 2,4-dinitrophenol, and (ii) at phosphorus, giving an unstable intermediate that undergoes a Lossen rearrangement yielding a series of derivatives including N,N-dialkylurea, undecylamine, undecyl isocyanate, and carbamyl hydroxamate.