Accession Number : AD0784726

Title :   Reduction by Sulphoxides: The Mechanism of Deoxygenation of Heterocyclic N-Oxides and Tertiary Amine N-Oxides,


Personal Author(s) : Biffin,M. E. C. ; Bocksteiner,G. ; Miller,J. ; Paul,D. B.

Report Date : 20 NOV 1973

Pagination or Media Count : 11

Abstract : Heterocyclic and tertiary amine N-oxides undergo an acid-catalysed deoxygenation by sulphoxides at elevated temperatures. The reductions are rationalized by postulating the formation of an initial coordination complex formed by attack of the nucleophilic N-oxide oxygen atom on the sulphur atom of the sulphoxide or its conjugate base. This complex may undergo an internal redox reaction to give a sulphone and amine or alternatively be attacked by a nucleophilic species (presumably sulphoxide oxygen) to produce a sulphinate and amine. Both decomposition pathways were observed. Deoxygenation of heterocyclic N-oxides, however, proceeds primarily by the second route and that of aliphatic amine oxides by the first decomposition process. These observations are rationalized mechanistically. The effect of varying the N-oxide substrates and the sulphoxides has also been examined. (Author)

Descriptors :   *Reduction(Chemistry), *Nitrogen heterocyclic compounds, *Sulfoxides, Amines, Oxides, Australia

Subject Categories : Organic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE