Abstract
The oxidation of a series of alkyl aryl sulfides promoted by the phthalimide N-oxyl radical (PINO) has been investigated by kinetic and product analysis. Sulfoxides are formed as major reaction products in the oxidation of thioanisoles and benzyl phenyl sulfides. The observation of fragmentation products in the oxidation of 2-phenyl-2-propyl phenyl sulfide and diphenylmethyl phenyl sulfide indicates that the reaction involves an initial electron transfer reaction from the sulfide to PINO with the formation of aryl sulfide radical cations and the anion PINO-. Combination of the species then leads to a radical adduct precursor of sulfoxides while the rapid C–S cleavage occurs with aryl sulfide radical cations that can form the stable 2-phenyl-2-propyl or diphenylmethyl carbocation.
GRAPHICAL ABSTRACT
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Disclosure statement
No potential conflict of interest was reported by the author(s).
Supplementary materials
Dependence of kobs for the decay of PINO on the concentration of aryl methyl sulfides. Hammett plot for the reaction of para-substituted thioanisoles with PINO. NMR and GC analysis of the oxidation of sulfides promoted by PINO.