Peroxomonosulfate oxidant

Peroxomonosulfate oxidizes VO ", the SOJ radical ion being involved in the mechanism. The oxidation of peroxovanadium(V), VO3, by HSO5 is catalyzed by VO, with a rate law rate = ki [HS05][VO ]o, being the rate constant found for the VO /HSOJ reaction. It is suggested that SOi, formed in the rate-determining step, oxidizes VO3 to... 

In general, peroxomonosulfates have fewer uses in organic chemistry than peroxodisulfates. However, the triple salt is used for oxidizing ketones (qv) to dioxiranes (7) (71,72), which in turn are useful oxidants in organic chemistry. Acetone in water is oxidized by triple salt to dimethyldioxirane, which in turn oxidizes alkenes to epoxides, polycycHc aromatic hydrocarbons to oxides and diones, amines to nitro compounds, sulfides to sulfoxides, phosphines to phosphine oxides, and alkanes to alcohols or carbonyl compounds. 

Among many other methods for epoxidation of disubstituted E-alkenes, chiral dioxiranes generated in situ from potassium peroxomonosulfate and chiral ketones have appeared to be one of the most efficient. Recently, Wang et /. 2J reported a highly enantioselective epoxidation for disubstituted E-alkenes and trisubstituted alkenes using a d- or L-fructose derived ketone as catalyst and oxone as oxidant (Figure 6.3). 

The kinetics of oxidation of several para-substituted anilines and aliphatic acetals by peroxomonosulfate in aqueous acetic acid have been investigated. In the oxidation of sulfides to sulfoxides by peroxymonosulfate (Oxone), the observed increase in second-order rate constants with increasing concentration of H2SO4 has been shown to be due to the increasing polarity of the medium, rather than to acid catalysis. Similar conclusions were arrived at for the oxidation of aryl thiobenzoates and thiol-phosphorus(V) esters. 

CZE-ELD, with a Au microelectrode at —0.6 V vs. SSCE and a Pt wire as auxiliary electrode, using sodium borate buffer and dodecyltrimethylanunonium bromide for dynamic coating of the capillary internal surface, can be applied for separation and determination of ultra-trace amounts of many oxidizing substances. Thus, the concentration of peroxodisulfate (S208 ) and peroxomonosulfate (S05 ) ions in pickling baths can be monitored by this method. The faster emergence of the heavier peroxodisulfate ion is attributed to different adsorption of the two analyte ions by the capillary coating . ... 

Chiral ketone-catalyzed asymmetric epoxidation has received intensive interest since the first reported by Curci et al. in 1984. The reaction is performed with oxone (potassium peroxomonosulfate) as the primary oxidant which generates the chiral dioxirane catalytic species in situ, which in turn, transfers the oxygen... 

The oxidation of 2,3-dimethylindole with peroxodisulfate and peroxomonosulfate yields 3-methy-lindole-2-carbaldehyde (136) (88JCS(P2)1065). The reaction proceeds in three steps, namely electrophilic attack of the peroxide at C-3 to give an indolenine intermediate (134), then peroxide attack on the enamine tautomer (135), and hydrolysis (Scheme 26) (93JOC7469). 

Potassium peroxomonosulfate, 259 Titanium(IV) isopropoxide, 311 of allylic, homoallylic alcohols t-Butyl hydroperoxide-Dialkyl tar-trate-Titanium(IV) isopropoxide, 51 t-Butyl hydroperoxide-Dibutyltin oxide, 53... 

In general, peroxomonosulfates have fewer uses in organic chemistry Uian peroxodisulfates. However, the triple salt is used for oxidizing ketones to dioxiianes, which in turn me useful oxidants in oiganic chemistry... 

Adam et al. subjected a series of meso-dihydrobenzoins to oxidative desymmetrization, using three equivalents of the chiral Shi ketone 54 as catalyst. In the presence of peroxomonosulfate (Oxone, Curox etc.), the latter generates a chiral dkmrane as... 

First-order dependence is observed with respect to both the oxidant and reductant in the oxidation of substituted anilines with peroxomonosulfate anion. Addition of acid causes retardation of the reaction. Yukawa-Tsuno correlation of the rates gave a negative reaction constant (p -1.7) and analysis of the effect of solvent in terms of Grunwald-Winstein equation (m 0.4) indicated an S -type reaction. 

Recently, Mello et al. have disclosed a simple and robust protocol for the generation of methyl(trifluoromethyl)-dioxirane from an aqueous solution of 1,1,1-trifluoroacetone hydrate, sodium bicarbonate, and peroxomonosulfate on a preparative scale (typically <2 g the authors suggest multiple iterations for larger scales). The methyl(trifluoro-methyl)dioxirane is removed from the reaction mixture by the evolved gases (O2, CO2) and has been applied to the oxidation of substrates in a second reaction zone (e.g., the epoxidation of cyclohexenone Scheme 33) <2007S47>. 

The composition of the oxidizing agent Oxone is 2 KHS05 KHS04 K2S04. The active component potassium monopersulfate (KHSO5, potassium peroxomonosulfate) is a salt from Caro s acid H2SO5. 

Potassium peroxomonosulfate (Oxone ) is also an effective oxidizing agent for the epoxidation of various alkenes in the presence of Mn porphyrin and a PT catalyst [79]. The biphasic epoxidation of various olefins is readily catalyzed by Co and Ni" phthalocyanines with NaClO as the oxygen donor and Bu4N" Br" as the PT agent [80]. The PTC oxidation of alkenes with NaClO is also catalyzed by square-planar Ni complexes [81-83]. 

Two other oxidants, potassium peroxomonosulfate and peroxodisulfate, were also tested but proved less efficient than potassium hexacyanoferrate(III). 

Shi and co-workers <97JOC2328, 97JA11224> have optimized their chiral dioxirane protocol for the asymmetric epoxidation of non-functionalized rra/i.v-olefins (e.g., 44), such that the chiral ketone 42 can be used in catalytic quantities with potassium peroxomonosulfate (Oxone) as the stoichiometric oxidant. The key to preserving the lifetime of the chiral auxiliary is pH control during the reaction the optimum range was found to be 10.5 or above, which is conveniently maintained with potassium carbonate. 

The methodology described above allows the asymmetric epoxidation of allylic alcohols or cis-substituted conjugated alkenes and the resolution of terminal epoxides. The asymmetric synthesis of trans-di- and trisubstituted epoxides can be achieved with the dioxirane formed from the fructose-derived ketone 64, developed by Shi and co-workers. The oxidizing agent potassium peroxomonosulfate... 

The peroxomonosulfate (PMS) oxidation of tartaric acid, catalysed by Cu(II) and Ni(II), was studied in the pH range 5.05-5.20 and 12.7. The reaction had an induction period and was autocatalysed. It was suggested that metal tartarates had undergone oxidative decarboxylation to an aldehyde, which formed the hemiacetal by reacting with the O -OH group of the tartarate ion. This reaction was the likely source of autocatalysis of the reaction. The similar oxidation of l-HA, studied in the presence and absence of Cu(II)-catalyst, was first order each in HA and PMS. The rate expressions for the uncatalysed and catalysed reactions were suggested. ... 

Other reactions that involved [Mn(TNH2PP)Cl MWCNT] as catalytic nanoreactor are the oxidation with sodium periodate of 2-imidazolines in MeCN [174] and the oxidative decarboxylation of a-arylcarboxylic acids with sodium periodate [175] (Scheme 14.8 a,b). On the other hand, iron(lll) me o-tetra(2-chlorophenyl)porphyrin, coordinated to hydroxyl-functionalyzed MWCNTs, catalyzed the oxidation of alkanes, alkenes, and sulfides using tetrabutylammo-nium peroxomonosulfate (BU4NHSO5) as oxygen source [176] (Scheme 14.8c). 

A wide range of sulfur radicals have been reported. Sulfur dioxide (S02 ), sulfite radical (SO ), sulfate radical (SOJ ) and peroxomonosulfate radical (SOs") can all be formed from sulfur dioxide, which is an environmental air pollutant, as well as from sulfites and bisulfites used as preservatives [114-118] and methods of their production and their reactivity has been previously reviewed [119]. Briefly, SOa acts as a one electron reductant whereas the others are all oxidising species with being the strongest one electron oxidant [117-119]. 

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