Hydrogen peroxide oxidation of sulfides

Sulfunes. A recent preparation of thietane 1,1-dioxide1 emphasizes the advantage of tungstic acid catalysis2 in the hydrogen peroxide oxidation of sulfides to sulfones an induction period is eliminated and the yield improved. 

The silica-supported benzisoselenazol-3(277)-one 117 (Scheme 42) was used as a heterogenous catalyst for hydrogen peroxide oxidation of sulfides to sulfoxides and sulfones, alkylarenes to the ketones and aromatic aldehydes to the arenecarboxylic acids. It exhibited appreciable activity and the results were similar to these when ebselen was a homogenous catalyst. It can be recovered from the reaction mixture simply, and reused <2004MI148>. 

Table 8.1 Hydrogen peroxide oxidation of sulfides to sulfoxides in fluorous phase .

A few benzisoselenazol-3(2//)-oncs were covalently immobilized to the solid support, either silica [165] or polymer [246] (147-150) (Fig. 8). They exhibited appreciable catalytic activity similar to the activity of ebselen. The most interesting prospective oxygen-transfer catalyst is benzisoselenazolone covalently bound to a silica support (147) named HALICAT. It has been applied to hydrogen peroxide oxidation of the sulfides and TBHP oxidation of the aromatic aldehydes and alky-larenes. The catalyst can be easily filtered off from the mixture after the reaction and reused several times [165],... 

Section 16 16 Oxidation of sulfides yields sulfoxides then sulfones Sodium metaper lodate IS specific for the oxidation of sulfides to sulfoxides and no fur ther Hydrogen peroxide or peroxy acids can yield sulfoxides (1 mole of oxidant per mole of sulfide) or sulfone (2 moles of oxidant per mole of sulfide)... 

The oxidation of sulfides to the corresponding sulfoxides and sulfones proceeds under rather strenuous conditions requiring strong oxidants such as nitric acid, hydrogen peroxide, chromic acid, peracids, and periodate. Using MW irradiation, this oxidation is achievable under solvent-free conditions and with desired selectivity to either sulfoxides or sulfones using 10% sodium periodate on silica (Scheme 6.34)... 

The flow-cell design was introduced by Stieg and Nieman [166] in 1978 for analytical uses of CL. Burguera and Townshend [167] used the CL emission produced by the oxidation of alkylamines by benzoyl peroxide to determine aliphatic secondary and tertiary amines in chloroform or acetone. They tested various coiled flow cells for monitoring the CL emission produced by the cobalt-catalyzed oxidation of luminol by hydrogen peroxide and the fluorescein-sensitized oxidation of sulfide by sodium hypochlorite [168], Rule and Seitz [169] reported one of the first applications of flow injection analysis (FTA) in the CL detection of peroxide with luminol in the presence of a copper ion catalyst. They... 

Various metallo-phthalocyanines (Pht) and metallo-tetraphenylporphyrins (TTP) have been tested as catalysts for the oxidation of sulfides into sulfones by hydrogen peroxide. TPPFe(III)Cl in ethanol was the only catalyst tested to give 100% conversion into sulfones in under 5 min sulfoxides were identified as intermediates. PhtFe(III) gave sulfoxides in 100% yield and PhtMn(III) and TPPMn(III)Cl gave the sulfoxides in up to 70% yields. The absence of any by-product, in particular disulfide,... 

SELECTIVE OXIDATION OF SULFIDES TO SULFOXIDES AND SULFONES USING HYDROGEN PEROXIDE IN THE PRESENCE OF ZIRCONIUM TETRACHLORIDE... 

The oxidation of sulfides is the most straightforward method for the synthesis of sulfoxides and sulfones.During recent years, very useful procedures involving aqueous hydrogen peroxide (H2O2) as the terminal oxidant are noteworthy due to the effective oxygen-content, low cost, safety in storage and operation and... 

In 2002, Ichihara and coworkers reported on the utilization of a Keggin-type phos-phomolybdate (NfLOsPMonOzu) on apatite as catalyst for the solvent-free epoxidation of olefins (see Section III.A.3.c) and the oxidation of sulfides and sulfoxides in the presence of urea hydrogen peroxide (Scheme 104)297. Chemoselectivities of the oxidation of the sulfides were good [product ratios (sulfide/sulfoxide) 84/16 up to 91/9] depending on the substrate, temperature and reaction time. 

Oxidation of sulfides and sulfoxides, as discussed above, and alkylation of sulfinate salts are the most common methods used to obtain sulfones for synthetic purposes [71, 109-113], A hydrogen peroxide-urea-phthalic anhydride system was recently proposed as a mild convenient reagent for the efficient preparation of sulfones from organic sulfides [114]. 

Chiral (salen)Mn(III)Cl complexes are useful catalysts for the asymmetric epoxidation of isolated bonds. Jacobsen et al. used these catalysts for the asymmetric oxidation of aryl alkyl sulfides with unbuffered 30% hydrogen peroxide in acetonitrile [74]. The catalytic activity of these complexes was high (2-3 mol %), but the maximum enantioselectivity achieved was rather modest (68% ee for methyl o-bromophenyl sulfoxide). The chiral salen ligands used for the catalysts were based on 23 (Scheme 6C.9) bearing substituents at the ortho and meta positions of the phenol moiety. Because the structures of these ligands can easily be modified, substantia] improvements may well be made by changing the steric and electronic properties of the substituents. Katsuki et al. reported that cationic chiral (salen)Mn(III) complexes 24 and 25 were excellent catalysts (1 mol %) for the oxidation of sulfides with iodosylbenzene, which achieved excellent enantioselectivity [75,76]. The best result in this catalyst system was given by complex 24 in the formation of orthonitrophenyl methyl sulfoxide that was isolated in 94% yield and 94% ee [76]. 

Trevisan V, Signoretto M, Colonna S, Pironti V, Strukul G (2004) Microencapsulated Chloroperoxidase as a Recyclable Catalyst for the Enantioselective Oxidation of Sulfides with Hydrogen Peroxide. Angew Chem Int Ed 43 4097... 

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