In search of a new class of stable nitroxide: synthesis and reactivity of a peri-substituted N,N-bissulfonylhydroxylamine

Patel, Bhaven, Carlisle, Julie, Bottle, Steven E., Hanson, Graeme R., Kariuki, Benson M., Male, Louise, McMurtrie, John C., Spencer, Neil and Grainger, Richard S. (2011) In search of a new class of stable nitroxide: synthesis and reactivity of a peri-substituted N,N-bissulfonylhydroxylamine. Organic & Biomolecular Chemistry, 9 (7). p. 2336. ISSN 1477-0520

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Official URL: http://dx.doi.org/10.1039/C0OB00976H

Abstract

Acyclic bissulfonylnitroxides have never been isolated, and degrade through fragmentation. In an approach to stabilising a bissulfonylnitroxide radical, the cyclic, peri-substituted N,N-bissulfonylhydroxylamine, 2-hydroxynaphtho[1,8-de][1,3,2]dithiazine 1,1,3,3-tetraoxide (1), has been prepared by formal nitrogen insertion into the sulfur–sulfur bond of a sulfinylsulfone, naphtho[1,8-cd][1,2]dithiole 1,1,2-trioxide. The heterocyclic ring of 1 is shown to adopt a sofa conformation by X-ray crystallography, with a pseudo-axial hydroxyl group. N,N-Bissulfonylhydroxylamine 1 displays high thermal, photochemical and hydrolytic stability compared to acyclic systems. EPR analysis reveals formation of the corresponding bissulfonylnitroxide 2 upon oxidation of 1 with the Ce(IV) salts CAN and CTAN. Although 2 does not undergo fragmentation, it cannot be isolated, since hydrogen atom abstraction to reform 1 occurs in situ. The stability and reactivity of 1 and 2 are compared with the known cyclic benzo-fused N,N-bissulfonylhydroxylamine, N-hydroxy-O-benzenedisulfonimide (6), for which the X-ray data, and EPR of the corresponding nitroxide 10, are also reported for the first time.

Item Type: Article
Uncontrolled Keywords: Acyclic bissulfonylnitroxides; peri-substituted N,N-bissulfonylhydroxylamine
Subjects: 500 Natural Sciences and Mathematics > 540 Chemistry & allied sciences
Department: School of Human Sciences
Depositing User: Bhaven Patel
Date Deposited: 30 Jun 2016 10:40
Last Modified: 30 Jun 2016 10:40
URI: http://repository.londonmet.ac.uk/id/eprint/1045

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