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

Patel, Bhaven and Carlisle, Julie and Bottle, Steven E. and Hanson, Graeme R. and Kariuki, Benson M. and Male, Louise and McMurtrie, John C. and 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

[img]
Preview
Text
c0ob00976h.pdf - Published Version

Download (1MB) | Preview
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 Mathemetics > 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

Actions (login required)

View Item View Item