Surface-Mediated Reactions. 8. Oxidation of Sulfides and Sulfoxides with tert-Butyl Hydroperoxide and OXONE¹

Solvent free permanganate oxidations

“…[1][2][3][4][5][6][7][8][9][10][11][12] In this paper we wish to describe a simple and general procedure that can be used for the oxidative transformation of many organic functional groups using an inexpensive and environmentally friendly oxidant, potassium permanganate. 13 Best results are obtained when KMnO 4 is first mixed with copper sulfate pentahydrate (or a 20/80 mixture of copper sulfate pentahydrate and alumina) to give a reagent that has previously been used extensively as a heterogeneous oxidant in inert solvents.…”

“…Aryl and alkyl sulfides are converted into the corresponding sulfones in good yields (reactions 7-13, tions of sulfides result in the formation of sulfoxides; [4][5][6] however, sulfoxides were not produced under these conditions. Addition of alumina to the solid support increased the rates of these reactions, but not the yields.…”

Montmorillonite impregnated with bismuth nitrate: A versatile reagent for the synthesis of nitro compounds of biological significance

“…Further, two solid adsorbents of identical structure with different surface area (particle size) can give different product distribution. Based on a recent publication, 15 we believe that the binding of bismuth nitrate to the free hydroxyl group of the multi-metallic montmorillonite is important and that this complex produces the nitronium ion. Clearly, the failure of bismuth nitrate to produce any product with alumina and only 70% with silica gel (under microwave irradiation), despite the presence of surface hydroxyl groups, strengthens the importance of the composition of the solid support.…”

7.28 Oxidation of Sulfur, Selenium, and Tellurium

“…Simple silica gel and alumina are also suitable promoters of sulfide oxidation by using TBHP or oxone. 119 Less acidic molecules, such as thiourea 17, are able to activate TBHP at only 1 mol% loading for the highly chemoselective oxidation of sulfides to sulfoxides (Scheme 12). 120 Alkyl, aryl, and functionalized sulfides are converted into sulfoxides in good-to-high yield at room temperature.…”