Sulfoxide or sulfone

Oxidation of a sulfide to a sulfoxide or sulfone is accompanied by a decrease m shield ing of the H—C—S—C proton by about 0 3-0 5 ppm for each oxidation... 

IV. MASS SPECTRA OF SOME ENVIRONMENTALLY AND PHARMACEUTICALLY SIGNIFICANT SULFOXIDES OR SULFONES... 

Similarly, only selected cyclic systems containing more than one sulfoxide or sulfone groups have been included and discussed here, primarily in the thietane (i.e. 1,2- and 1,3-dithietanes) and thiane (i.e. 1,2-, 1,3- and 1,4-dithianes) series. The criterion for the inclusion of these multifunctional heterocycles was their contribution to the understanding of the physical properties and chemical reactivity of cyclic sulfones and sulfoxides, and the effects of these groups on either their immediate vicinity or on the behavior of the whole molecule. 

Carbon-13 chemical shifts of the a- and (8-carbon atoms of various unsubstituted and 3-substituted thietane oxides and dioxides have been recorded and correlated by the equations S = ay + bx and Sf = ax + by where a and b are parameters characteristic of the sulfoxide or sulfone (y) and the substituent (x)216. The values of the substituent parameters were found to parallel those which determine the effect on the 13C chemical shifts when hydrogen is replaced by a substituent224. 

The syntheses of perhalogenated dithiethanes and their oxidation products (214-219) have been recently reported247. The method is based on the photochemical dimerization of thiophosgen or its fluoro- and bromo-analogues followed by partial oxidation with trifluoroperacetic acid to the desired sulfoxides (or sulfones)248 as shown in equation 84. 

Several typical reactions of cyclic sulfoxides or sulfones are not observed in the acyclic and large-ring sulfoxide and sulfone analogues, or if they are, they take a different path. In such cases the effect of the cyclic sulfoxide or sulfone function is at least partially a consequence of the particular stereochemical constraints of the cyclic array. 

The steric requirements of the enhanced interaction between arylsulfinyl or arylsulfonyl groups and the benzene ring in bis(4-hydroxyphenyl)sulfoxides or sulfones were examined by Oae and colleagues through the introduction of methyl groups in two or four of the positions ortho to SO or S02. As in the work described earlier for S02Me, effective values for the combined influence of the substituents o (obs.) were determined and compared with o (calc.) computed on the basis of strict additivity of substituent effects on the dissociation... 

Cation and anion radicals form from sulfoxides or sulfones by either chemical or electrochemical oxidation and reduction, respectively. The ability of compounds to accept... 

The radical anions of dialkyl sulfoxides (or sulfones) may be obtained by direct capture of electron during y-irradiation. It was shown that electron capture by several electron acceptors in the solid state gave anion adducts 27. It was concluded276 that these species are not properly described as radical anions but are genuine radicals which, formed in a solid state cavity, are unable to leave the site of the anions and exhibit a weak charge-transfer interaction which does not modify their conformation or reactivity appreciably, but only their ESR spectra. For hexadeuteriodimethyl sulfoxide in the solid state, electron capture gave this kind of adduct 278,28 (2H isotopic coupling 2.97 G is less than 3.58 G normally found for -CD3). 

TABLE 6. ESR parameters for radical cations arising from sulfoxides or sulfones... 

The electron transfer reaction from fluorenyl carbanions adjacent to sulfoxide or sulfone (9) to fluorenone (FIO) has been studied by means of flash photolysis37. For n — 1 as well as n — 2 the transient F10T, M + (contact ion pair) appeared in THF and F10T(free ion)... 

Caron, G., Gaillard, P., Carrupt, P. A., Testa, B. Lipophilicity behavior of model and medicinal compounds containing a sulfide, sulfoxide, or sulfone moiety. 

Data presentations should include the parent compound and all toxic transformation products. This is particularly important for oxidation of sulfide linkages to sulfoxides or sulfones. These products are often equally toxic to the parent with increased availability. Attention should also be given to oxidative desulfuration of phosphorothionate esters. 

Oxime carbamates have high polarity and solubility in water and are relatively chemically and thermally unstable. They are relatively stable in weakly acidic to neutral media (pH 4-6) but unstable in strongly acidic and basic media. Rapid hydrolysis occurs in strongly basic aqueous solutions (pH > 9) to form the parent oxime/alcohol and methylamine, which is enhanced at elevated temperature. Additionally, oxime carbamates are, generally, stable in most organic solvents and readily soluble in acetone, methanol, acetonitrile, and ethyl acetate, with the exception of aliphatic hydrocarbons. Furthermore, most oxime carbamates contain an active -alkyl (methyl) moiety that can be easily oxidized to form the corresponding sulfoxide or sulfone metabolites. 

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