Synthesis and Decomposition of Some Dialkyl Oxide Derivatives of Organotrisulfides

Abstract

The isolation or detection of sulfenic sulfonic thioanhydrides 1 (e.g., 6), sulfenyl vic-disulfoxides 4 (e.g., 9, 14), and sulfinic thioanhydrides 5 (e.g., 20) has been carried out by oxidative procedures at various temperatures. The decomposition of these compounds has been investigated and is shown to be consistent with the mechanism proposed for the decomposition of trisulfide monoxides.

Synthesis and Decomposition of Tri- and Tetraoxide Derivatives of Dialkyl Trisulfides

“…In contrast with previously reported low-temperature experiments, , the reaction mixture obtained at −40 °C is very clean and no intermediates can be detected. Therefore, if the reaction was taking place at the central sulfur, the very reactive di- tert -butyl vic -trisulfoxide ( 9 ) should be formed and would then rearrange to the corresponding trioxide 5 .…”

“…Therefore, if the reaction was taking place at the central sulfur, the very reactive di- tert -butyl vic -trisulfoxide ( 9 ) should be formed and would then rearrange to the corresponding trioxide 5 . By analogy with our previous work, the spectra recorded at −40 °C should at least show the presence of some intermediate if 9 was not stable enough at this temperature. In addition, all the reactions that involve a rearrangement of this type ,, give complex mixtures of final products in contrast with the results observed here.…”

“…By analogy with other oxidations of polysulfides, , the electrophilic oxidation of 8 is regiospecific and only delivers 5 in high yield. According to current thinking, the peracid oxidation of 8 should take place at the sulfenyl central sulfur which is believed to be more electron rich than the sulfinyl external sulfur (eq 2).…”

A Divergent Strategy for Site‐Selective Radical Disulfuration of Carboxylic Acids with Trisulfide‐1,1‐Dioxides

“…7). [29] Thestrikingly similar rate constants prompted us to reconsider our proposed mechanism:c ould the trisulfide dioxide simply be as ource of tetrasulfide that reacts with alkyl radicals?I ndeed, we found that the decomposition of trisulfide dioxide 2c could deliver the tetrasulfide under the standard disulfuration reactions conditions.H owever,a fter 14 hours (the time for which the foregoing preparative reactions were run), less than 15 %o ft etrasulfide was observed, [30] which indicates that it cannot be the principal disulfuration reagent in the reactions of the trisulfide dioxides.T his was reinforced by the results of ad irect competition experiment utilizing differently substituted tetrasulfide and trisulfide dioxide that give rise to unique disulfide products upon substitution. In each case,t he predominant product observed was derived from alkyl radical substitution of the trisulfide dioxide (see the Supporting Information for details).…”

A Divergent Strategy for Site‐Selective Radical Disulfuration of Carboxylic Acids with Trisulfide‐1,1‐Dioxides

“…Indeed, we found that the decomposition of trisulfide dioxide 2 c could deliver the tetrasulfide under the standard disulfuration reactions conditions. However, after 14 hours (the time for which the foregoing preparative reactions were run), less than 15 % of tetrasulfide was observed, [30] which indicates that it cannot be the principal disulfuration reagent in the reactions of the trisulfide dioxides. This was reinforced by the results of a direct competition experiment utilizing differently substituted tetrasulfide and trisulfide dioxide that give rise to unique disulfide products upon substitution.…”