Structure and reactivity of halosulfonium salts

Chemoselective reaction of a sulfonate ester with methoxide ions in preference to benzyl mercaptide anions

“…In eq. [4], the corresponding nucleophilic attack at the sp2 carbon results in substitution by an addition-elimination sequence. A simple test of the pathway by which benzyl methyl sulfide forms would involve replacing the methanol/methoxide of eq.…”

7.28 Oxidation of Sulfur, Selenium, and Tellurium

“…188 However, propargyl or (methoxycarbonyl)methyl sulfides react with tBuOCl in an alcoholic solvent to give the corresponding a-alkoxy sulfides rather than the sulfoxides. 189 Easy-to-handle calcium hypochlorite has been used with moist alumina to conveniently accomplish the chemoselective oxidation of sulfides to sulfoxides bearing various functional groups, such as carbonyl groups in aldehydes and ketones, nitriles, halides, ethers, hydroxyls, olefinic, and allylic double bonds. 190 Under controlled reaction conditions, Ca(OBr) 2 serves as an effective oxidizing agent for the selective oxidation of differently substituted allylic sulfides to the sulfoxides in high yield without observing bromination of the aromatic ring or oxidation of the C-C double bond to give epoxides or halohydrins (Scheme 19).…”

Mechanism for the reactions of sulfides with hypochlorous acid and N‐chlorosulfon‐amides: Formation of solvated chlorosulfonium cation and λ4‐sulfane intermediates

“…The calculated total energy decreases at the solvation for all of species; however, free energy decreases also at the solvation of ions (cf. ΔE o and ΔG o values in the SI in Table S1 for entries [14][15][16][17][18][19].…”

“…It must be mentioned, however, that the supposed chlorosulfonium cation and λ 4 ‐sulfane intermediates have never been isolated or detected in reaction mixtures containing nucleophiles and protic solvent. Chlorosulfonium salts and λ 4 ‐sulfanes can be prepared only in nonnucleophilic and aprotic media.…”