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DOI: 10.1039/A704761D (Paper) Reference Section for: J. Chem. Soc., Perkin Trans. 2, 1998, 393-400

Oxidation of N-benzyl-N-methylhydroxylamines to nitrones. A mechanistic study

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Azfar Hassan, Mohammed I. M. Wazeer and Sk. Asrof Ali

Abstract

Oxidation of various N- (o-, m-, p- substituted benzyl)-N-methylhydroxylamines has been carried out using mercury(II) oxide and p-benzoquinone ([hair space]p-BQ) as oxidants. Hammett plots have been obtained with negative ρ values, showing the development of a positive centre in the transition state. The unstable E nitrones, which readily isomerize to the more stable Z nitrones, are obtained in appreciable quantities and in some cases as the major product. A considerable deuterium isotope effect is observed in the oxidation process. The overall picture of the mechanistic pathway involves electron transfer from nitrogen to the oxidant followed by hydrogen abstraction.

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