Practical oxidation of sulfides to sulfones by H2O2 catalysed by titanium catalyst

Abstract

The oxidation of thianisole and other substituted arylalkyl and diaryl sulfides with aqueous H 2 O 2 as the oxidant and heterogeneous TiO 2 catalyst exhibits a high selectivity affording the corresponding sulfones with 80-98% isolated yields. It should be noted that H 2 O 2 provided better results as compared with t BuOOH in terms of the reaction rate and yields of sulfones. The use of hydrogen peroxide and heterogeneous nanocrystalline titania catalyst is a green alternative to the traditional stoichiometric oxidation providing high yields of sulfones in one step.

Titanium dioxide doped with vanadium as effective catalyst for selective oxidation of diphenyl sulfide to diphenyl sulfonate

“…Titanium dioxide doped with vanadium as effective catalyst for selective oxidation of diphenyl… 1477 many authors that transformation of sulfides to sulfones proceeds via the sulfoxides intermediates [7,9]. Thus, the progress in Ph 2 S oxidation can be determined by analysis of the substrate conversion as well as the progress in selectivity.…”

“…The interest in organic sulfoxides and sulfones production continuously increases due to their importance as synthetic intermediates for production of a broad range of chemically and biologically active substances, which can be used as therapeutic agents in many ailments including: antiulcer (proton-pump inhibitor) [1], antibacterial, antifungal, antiatherosclerotic [2], antihypertensive [3] and cardiotonic agents [4], as well as psychotronics [5] and vasodilators [6]. Many various oxidants (e.g., KMnO 4 , HNO 3 , RuO 4 ) have been used for sulfide oxidation, but most of them are not suitable as catalysts to a large-scale operation for several reasons [7]. Most of them are characterized by high costs of production, low content of effective oxygen and formation unfavorable co-products during oxidation process [8,9].…”

“…Among various methods of organic sulfoxides and sulfones synthesis direct catalytic oxidation of sulfides using H 2 O 2 as oxidizing agent seems to be one of the most promising [7]. Hydrogen peroxide is not only effective oxidant, but also environmental-friendly because does not result in the formation of any harmful or toxic by-products.…”

7.28 Oxidation of Sulfur, Selenium, and Tellurium

“…Heterogeneous systems such as SiO 2 -TiO 2 mesoporous xerogels, 249 nanocrystalline TiO 2 particles, 250 Pd/Ti based nanoparticles, 251 or tetrameric titanium alkoxide/ionic liquid 252 have been successfully used with H 2 O 2 in the oxidation of sulfides to sulfones. Commercially available and stable ammonium heptamolybdate catalyzes the oxidation of alkyl aryl and alkyl heteroaryl sulfides to sulfones in excellent yield with H 2 O 2 as oxygen source at room temperature in methanol (Scheme 26).…”

Highly Selective Oxidation of Sulfides to Sulfones by H2O2 Catalyzed by Porous Capsules

“…In contrast, oxidation of sulfides with H 2 O 2 is the most attractive because it is cheap, environmentally benign, safe in storage and operation, readily available and easy to handle with effective oxygen content [9,10]. Different catalysts such as polyoxometalates, acid catalysts, enzymes, and metal catalysts have been used for the oxidation of sulfides [11][12][13][14][15]. Polyoxometalates (POMs) are a class of metal oxide nanoclusters offering rich structural versatility, accessibility and different applications in the fields of analytical chemistry, medicine, electrochemistry, photochemistry, and catalysis [16][17][18].…”