The Oxidation of Thiols with DMSO-SbCI₅(1:1) Complex

Abstract

In the reaction of thiophenol [1], 4-methylbenzenethiol [2], 4-nitrobenzenethiol [3], α-toluenethiol [4] and 1-dodecanethiol [13] with DMSO-SbCl₅(1:1) complex, the corresponding sulfides were given over 81% yield under the mild conditions (Table 1 and Table 2).1, 2-Dithiolane [11] and 1, 2-dithiane [12] were also obtained in high yields of 90.7% and 73.2% respectively in the reaction of 1, 3-propanedithiol [5] and 1, 4-butanedithiol [6] with the complex. Both DMSO and SbCl₅ in the complex seem to be concerned as an oxidant as shown in the following equation.
4RSH + DMSO SbCl₅→ 2R-S-S-R (CH₃)₂S SbCl₃ + 2HCl H₂O
When tribenzylamine was added in each reaction mixture of [1], [2], [3] and [4] with the complex, the yield of the corresponding sulfides increased in the range of 3% to 10% (Tnble 7).