Fp. Ballistreri et al., THE RELATIVE REACTIVITY OF THIOETHERS AND SULFOXIDES TOWARD OXYGEN-TRANSFER REAGENTS - THE CASE OF DIOXIRANES, Tetrahedron letters, 35(43), 1994, pp. 8041-8044
In the competitive oxidation of thioethers and sulfoxides by electroph
ilic reagents the reactivity ratio may be small enough to cause the fo
rmation of mixtures of products. This has been studied in the reaction
of dimethyldioxirane, DMD, and trifluoromethyl-methyldioxirane, TMMD.
In particular TMMD oxidizes both thioethers and sulfoxides whereas DM
D attacks only thioethers. By applying the logic which has been used t
o develop mechanistic probes based on such competitive oxidations, the
unrealistic conclusion that TMMD is less electrophilic than DMD would
be reached On the contrary we show also by means of Hammett plots on
substituted sulfoxides that DMD and TMMD are both electrophilic oxidan
ts toward sulfoxides and that TMMD is less selective than DMD being a
stronger oxidant.