Synthesis of Vinyl Sulfones via I₂‐mediated Alkene Sulfonylations with Thiosulfonates

Abstract

A simple sulfonylation strategy involving I2 and thiosulfonates, as sulfonyl‐group precursors, is reported for the synthesis of vinyl sulfones. Sulfonyl radicals are presumed to be generated from thiosulfonates, which subsequently react with styrene or cinnamic acid derivatives to afford a variety of vinyl sulfones under the described reaction conditions. Detailed conditions, the substrate scope, and mechanistic studies are discussed.

Disulfides as versatile starting reagents: effective sulfonylation of alkenes with disulfides under electrochemical conditions

“…Anodically generated iodine reacts with the starting disulfide 2a, resulting in sulfonium cation A, 53 which is then converted into thiosulfinate B with the use of water. [54][55][56] Subsequent similar reactions of B with iodine and water lead to thiosulfonate C. A further reaction between C and iodine provides sulfonium cation D, 57 which is, in the presence of iodide, decomposed into sulfonyl iodide E and sulfenyl iodide F. The S-I bond of the former is cleaved, and sulfonyl radical G is generated. Sulfenyl iodide F can be cathodically reduced, regenerating the starting disulfide 2a.…”

Study on the Application of Thios/Selenium Sulfonates as Radical Reagent

“…2018 年, Jang 课题组 [59] 反应生成磺酰碘化物 147 [60][61] . [63] . 在引入苯乙烯后生成中间体 159, 氧与 159 反应形成过氧自由基, 然后被另一分子 159 捕获, 再经过氧键的均裂形成中间体 160 [64][65]…”

Thiosulfonates as Emerging Reactants: Synthesis and Applications

“…The role of oxygen is assumed to involve the removal of the thiol R 2 SH by‐product by forming disulfide ( 3 ). Iodine can also promote the formation of sulfonyl radicals ( 111 ) from thiosulfonates, which subsequently react either with styrenes or cinnamic acids ( 243 ) to afford a range of synthetically interesting vinylsulfones ( 241 ) in moderate to good yield (route 2) …”

“…[170] Allyl vinyl thioethers (189)w ere synthesized by the reactiono favinylalanate 187 with an allyl thiosulfonate (188)( Scheme 74). [171] Vinylalanate 187 was prepared by the cis-hydroalumination of an alkyne (186) followed by reaction with n-BuLi. Subsequent cleavage of the carbon-aluminiumb ond with electrophile 188 deliversa na llyl vinyl thioether (189)w ith E-stereochemistry at the vinyl moiety.…”

“…Iodine can also promote the formation of sulfonyl radicals ( 111)f rom thiosulfonates, which subsequently react either with styrenes or cinnamic acids (243)t oafford arange of synthetically interesting vinylsulfones (241)i nm oderate to good yield (route 2). [186] Shen designed S-(difluoromethyl) benzenethiosulfonate (95)asapowerful reactant for radical difluoromethylsulfenylation of aryl-and alkylboronic acids (244)i nt he presence of silver nitrate as catalyst (Scheme 88, route 1). [119] Unfortunately,t he authors did not propose am echanism for this transformation.…”