Oxidation of disulfides with electrophilic halogenating reagents: concise methods for preparation of thiosulfonates and sulfonyl halides

Facile synthesis of symmetric thiosulfonates by oxidation of disulfide with oxone/MX (MX = KBr, KCl, NaBr and NaCl)

“…Figure 1. The easy recognizable doublet of protons of 1a at δ = 7.24 ppm gradually down field shifted to δ = 7.66 ppm and δ = 8.18 ppm corresponding to the formation of the thiosulfonate (2a) 11 within 20 minutes. It is worthy to mention that in addition to the KBr, other alkali-metal chlorides and bromides such as NaBr, KCl and NaCl also yielded 2a in quantitative yield (Table 2).…”

“…However, this procedure cannot be suitable for the synthesis of unsymmetric thiosulfonates as a mixture of products (Scheme 2) were noticed. It is believed that the oxidation proceeds via the formation of hypohalous acid, 11 which has higher instability due to pronounced ionic nature and thus more reactivity towards the disulfides leading to a mixture of products. 7 Scheme 2.…”

“…Therefore, considerable efforts have been made in the development of both symmetric-and antisymmetric thiosulfonates. 3 Among, the most frequently employed method for the synthesis of symmetric thiosulfonates involve the direct oxidation of disulfides in the presence of various promoting reagents such as ceric ammonium nitrate/iodine, 4 chlorine/acetic anhydride, 5 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate), 6 dibromo hydantoin, 7 dinitrogen tetroxide/charcoal, 8 dinitrogen tetroxide supported on poly(vinylpyrrolidone), 9 dichlorodioxomolybdenum, 10 1-fluoro-2,4,6-trimethylpyridinium trifloromethanesulfonate, 11 hydrogen peroxide/titanium tetrachloride, 12 3-chloroperbenzoic acid, 13 N-bromophthalimide, 7 N-bromosuccinimide, 14 N-chlorophthalimide, 7 Nchlorosuccinimide, 11 scandium tris(trifluoromethanesulfonate), 15 silica sulfuric acid/sodium nitrite, 16 sodium periodate 17 and zinc dichromate trihydrate. 18 However, many of these methods have their own merits and demerits including long reaction times, drastic reaction conditions, use of volatile and toxic organic solvents, undesirable side reactions, laborious workup procedures, usage of expensive reagents, special treatment for the activation of the reagent and unsatisfactory yields.…”

“…As a consequence, the exploitation of highly practical and more selective reagents is very desirable and remains a challenging area for exploration. 11 Oxone (potassium peroxymonosulfate, KHSO 5 ⋅KHSO 4 ⋅K 2 SO 4 , 2:1:1 molar ratio) is a commercially available effective oxidant. 19 Due to its high stability, nontoxicity, water-solubility, ready accessibility and high efficiency, has been widely used for the oxidations of a wide range of functional groups including acetals, 19 alcohols, 19 aldehydes, 19 alkenes, 19 amines, 19 arenes, 19 imines, 19 nitroalkanes 19 and oximes.…”

Fast and efficient green synthesis of thiosulfonate S-esters by microwave-supported permanganate oxidation of symmetrical disulfides

“…[16,17] Symmetrical disulfides can also be converted into the corresponding thiosulfonates by chlorosolvolysis [18][19][20][21] and by means of Selectfluor TM (1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate)). [22,23] Since a symmetrical disulfide is the product formed primarily upon oxidation of a thiol, it has naturally been attempted with some success to synthesize "symmetrical" thiosulfonates directly from thiols, for example, by means of chlorosolvolysis [21] and by oxidation with dinitrogen tetraoxide [24][25][26] or hydrogen peroxide in the presence of titanium tetrachloride. [27] Very recently the direct oxidation of thiols into the corresponding thiosulfonates by means of zinc dichromate trihydrate has also been reported.…”