Oxidation 1,1,1-trifluoroacetone

Other ketones besides acetone can be used for in situ generation of dioxi-ranes by reaction with peroxysulfate or another suitable peroxide. More electrophilic ketones give more reactive dioxiranes. 3-Methyl-3-trifluoromethyldioxirane is a more reactive analog of DMDO.99 This reagent, which is generated in situ from 1,1,1-trifluoroacetone, can oxidize less reactive compounds such as methyl cinnamate. 

Fig. 4.12 Enhancement of Zn(ll) extraction, D Do, from 1 M NaC104 into carbon tetrachloride containing the complexing extractants acetylacetone (O), trifluoroacetone (A), or hexafluoroacetone ( ) as a function of the concentration of the adduct former trioctyl phosphine oxide (B). The curves are fitted with Eq. (4.50) using the constants log Km = 3.01 (AA), 6.70 (TEA), 7.0 (TEA), and Km = 4.66 (AA), nil (TEA), 11.6 (HEA). (Erom Ref. 24.)...

Oxidation of episulfides to episufones using Oxone/trifluoroacetone was reported for the first time (equation 55). ... 

Solvent extraction by tributyl phosphate (TBP) (13, 96), dithizone (20, 71, 72), cupferron (89), thenoyl trifluoroacetone (TTA) (55), diiso-propyl ketone (26), mesityl oxide (92), tri-n-benzylamine and methyl di-n-octylamine (99), diisopropyl and diisobutyl carbinol (100) have all found some application on the trace scale. Acetylaeetone and methyl isobutyl ketone extract milligram amounts of polonium almost quantitatively from hydrochloric acid, but the stable polonium-organic compounds which are formed make it difficult to recover the polonium in a useful form from solutions in these ketones (7). Ion exchange (22, 115, 119) and paper chromatography (44, 87) have also been used for trace scale separations of polonium, but the effects of the intense alpha-radiation on organic com-... 

Johnson and Taylor have shown that for the first tune episulfones may be prepared by oxidation of a variety of the corresponding mono- and bi-cyclic episulfides using oxone-trifluoroacetone, although r/. v-stilbene and cyclohexene episulfides failed.197 Preliminary mechanistic studies indicated that neither TFDO or Oxone alone was the... 

Studies of vanadyl diketonate complexes VO(dik)2L (L = heterocyclic amine) continue. The stability constants of VCKdik L1 (L1 = 4-methylpyridinelV-oxide) fall in the series dik = thenoyltrifluoroacetone (tta) > trifluoroacetone (tfa) > dbm > bzac > acac > dpm whereas the pKa s of the diketones fall in the series dbm > bzac > acac > tta > tfa.409 The i.r. spectra of the complexes in solution show two... 

Ketones can be converted to dioxiranes by Oxone (2KHSO5 KHSO4 K2SO4) under shghtly alkaline conditions (pH 7-8) (400). The dioxirane of 1,1,1-trifluoroacetone is a powerful yet selective oxidant under mild conditions, typically at temperatures below 313 K (10). Exemplary reactions are stereospecific olefin epoxidation and hydroxylation of tertiary C-H groups, or ketonization of CH2 groups. With chiral ketones, even enantioselective reactions are possible (401). Although the reactions are often performed in excess ketone, it is actually possible to use the ketone in a catalytic fashion, for example, for 1,1,1-trifluoroacetone (Scheme 5). 

Thiirane A,A-dioxides are quite unstable and are difficult compounds to make. The first stable thiirane A,A-dioxide was synthesized by oxidation of a thiirane using a mixture of Oxoneu/trifluoroacetone (Oxone = 2KHSO5KHSO4K2SO4) (Scheme 63) <1997TL5873>. 

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>. 

Methyl(trifluoromethyl)dioxiiane (TFDO), prepared from 1,1,1-trifluoroacetone and KHSOg, is more reactive than DMDO by a factor of 600. In addition to facile epoxidation of alkenes, TFDO can be used to regioselectively oxidize tertiary over secondary C-H bonds via an oxenoid (butterfly) mechanism. ... 

Activation. Hexafluoro-2-propanol, trifluoroacetone, and chiral arenesulfo-nimidoylimidazoles represented by 1 are useful activators of HjOj for oxidation of sulfides, epoxidation of allylic alcohols, and some other reactions. 

Episulfones. Episulfones can be isolated when episulfides are oxidized with Oxone -trifluoroacetone. 

First synthesized and characterized in 1988, ° this dioxirane (TMDO) is generally prepared by oxidation of 1,1,1-trifluoroacetone with potassium monoperoxosulfate (caroate). Yellow solutions of TMDO are quite stable at 20°C. It has also been generated in homogeneous organic solutions up to 1 M by oxidation with arenesul-fonic peracids, formed in situ from the sulfonic acid, H2O2, and NaOH. ... 

Treatment of TMDO (54) with trimethylamine oxide or nucleophilic anions results in the formation of singlet oxygen. Chloride ion, for example, is first oxidized to hypochlorite ion, which then attacks another molecule of the dioxirane. Fragmentation ensues, producing trifluoroacetone, singlet oxygen, and regenerated chloride ion. 

An early conventional method for plutonium analysis was coprecipitation in acid solution with a rare earth fluoride, dissolution in aluminum nitrate solution with sodium nitrite to maintain the 4-4 oxidation state, and extraction into thenoyl-trifluoroacetone (TTA) in benzene. Plutonium was back-extracted into dilute HCl, the acid was evaporated, and plutonium was taken up in HCI-NH4CI solution... 

The quenching of the luminescence of lanthanide complexes by the presence of water [51] can be supressed by encapsulating lanthanide complexes such as, e.g., europium-P-diketonato complexes (europium-(2-naphthoyl trifluoroacetone)3, (Eu(NTFA)3, and europium-(2-naphthoyl trifluoroacetone)3(trioctylphosphine oxide)2, (Eu(NTFA)3(TOPO)2), in polystyrene (PS) nanoparticles. The luminescence observed in aqueous dispersions and the increase of luminescence lifetime indicate protection from the environmental water [52]. 

Production of superoxide radical anion (02 ) during oxidation of dihydroorotate in rat hver mitochondria was not affected by antimycin A, thenoyl-trifluoroacetone, or added ubiquinone but was inhibited by orotate, a product inhibitor of dihydroorotate dehydrogenase (Forman and Kennedy 1975). It appears likely that superoxide is generated at the primary dehydrogenase. Dihydroorotate dehydrogenase differs from succinate dehydrogenase both in its utilisation of ubiquinone and in the mechanism of cytochrome b reduction. Formation of orotate is only partially inhibited by thenoyltri-fluoroacetone and the inhibitor does not prevent the reduction of cytochrome by dihydroorotate. 

Oxone sulfoxidations can show appreciable diastereoselectiv-ity in appropriate cases, as demonstrated in eq 26. Enantio-selective oxidations of sulfides to sulfoxides have been achieved by buffered aqueous Oxone solutions containing bovine serum albumin (BSA) as a chiral mediator (eq 27). As little as 0.05 equiv of BSA is required and its presence discourages further oxidation of the sulfoxide to the sulfone. Oxone can be the active oxidant or reaction can be performed in the presence of acetone, trifluoroacetone, or other ketones, in which case an intermediate dioxirane is probably the actual oxidizing agent. The level of optical induction depends on structure of the sulfide and that of any added ketone. Sulfoxide products show ee values ranging from 1% to 89%, but in most examples the ee is greater than 50%. 

Scheme 18.18 1,1,1-Trifluoroacetone as oxidant for Al-catalysed Oppenauer oxidation.

The group of Asensio investigated the role of 1,1,1-trifluoroacetone as a suitable hydride aeeeptor in the oxidation under mild eonditions of secondary alcohols in the presence of diethylethoxyaluminium as catalysts (experimental conditions in dichloromethane/toluene, RT, 1 h, molar ratio substrate/trifluoroacetone 1/2 with 30 mol% cat.). Interestingly the oxidation is selective, affording the ketones from the secondary alcohols quantitatively e.g. cyclohexanone after 8 h or adamantanone in 1 h) and leaving primary alcohols unreacted under similar reaction conditions, as shown in Scheme 18.18. ... 

Structural studies of polymer surfaces materials that have been studied include polymethyl methacrylate (PMMA) [22], PMMA-polypyrrole composites [23], poly(chloromethyl styrene) bound 1,4,8,11 tetrazacrylotetra decane poly(chloromethyl styrene) bound theonyl trifluoroacetone [24], polydimethyl siloxane-polyamide copolymers [25], PS [26], ion-implanted PE [27], monoazido-terminated polyethylene oxide [28], polyurethanes [29], polyaniline [30], fluorinated polymer films [31], poly(o-toluidine) [32], polyetherimide and polybenzimidazole [33], polyfullerene palladium [34], imidazole-containing imidazolylethyl maleamic acid - octadecyl vinyl ether copolymer [35], polyphenylene vinylene ether [36], thiphene oligomers [37], fluorinated styrene-isoprene derivative of a methyl methacrylate-hydroxyethyl methacrylate copolymer [38], polythiophene [39], dibromoalkane-hexafluorisopropylidene diphenol and bisphenol A [40], and geopolymers [41],... 

The kinetics of the thermal decomposition of 1,1,1-trifluoroacetone have been studied, both in the presence and absence of foreign gases (e.g., nitric oxide, propene, perfluoropropene). The following reactions were written to account for the predominant products from pyrolysis of the ketone alone at 547 °C and initial pressure 106 mmHg ... 

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