Sulfone-N-oxides

Deoxygenation of oxides.1 Sulfoxides, sulfones, N-oxides, and phosphine oxides can be deoxygenated by Sml2 in THF/HMPT at 20-65°. HMPT is essential for high yields. 

Sulfone-N-oxides from aminosulfones s. 15, 126 Hydrogen peroxide acetic acid H202/CHgC00H... 

Hydrogen peroxide hydrochloride Sulfoxides and sulfones from thioethers Sulfone-N-oxides from aminosulfones... 

Alkyl- and aryl-thiopyridazines are oxidized to sulfoxides, sulfones or sulfonic acids, depending on the reaction conditions. N- Oxidation can take place simultaneously. 

Nucleophilic addition of lithiated sulfones to nitrones made it possible to develop new stereoselective approaches to the synthesis of pyrrolidine-N -oxides based on a reverse-Cope-type elimination. One method is based on the reaction of lithiated sulfones with nitrones (386) (Scheme 2.168) (625). 

Dimethylpyridine N-oxide and 1,2-allenyl sulfone in CHC13 at room temperature gave the 1,3-dipolar cycloaddition product 229, which subsequently underwent a [l,5]-sigmatropic rearrangement and a migration of the C=C bond to afford 231. The [2 + 2]-cycloaddition of the C=N bond in 231 with the terminal bond in propadie-nyl sulfone would deliver the tricyclic product 232 [123]. 

Abstract This chapter principally concerns oxidations of organic substrates containing N, O, S, P, As and Sb. Oxidations of amines are covered first, including primary amines to nitriles or amides secondary amines to imines or other products tertiary amines to N-oxides or other prodncts (Section 5.1) and the oxidation of amides (5.2). Oxidation of ethers to esters or lactones follows (5.3), then of sulfides to sulfoxides or sulfones (5.4) and of phosphines, arsine and stibines to their oxides (5.5). A final section (5.6) concerns such miscellaneous oxidations not covered by other sections in the book. 

N-Oxides, sulfoxides, sulfones.2 The hydroperoxide oxidizes tertiary amines to N-oxidcs (60 95% yield) and sulfides to sulfoxides (1 equivalent) or to sulfones (2 equivalents). 

Alternatively, N-hyroxypyridine-2-thione, a versatile antibacterial and antifungal agent commercially available as Omadine, has been used. As expected, in the presence of DNA its photolysis causes SSBs (via OH), but after its photolytic consumption continuing photolysis at 350 nm caused the photooxidation of G in DNA and in dGuo (Adam et al. 1999). Apparently this effect is induced by one of its photolytic products that are largely the N,AT-dioxide, the mono-N-oxide, the disulfide and the sulfonic acid (Adam et al. 1999). 

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