Low-temperature oxidation of sulfur dioxide by molecular oxygen in aqueous solutions of non-transition metals trifluoroacetates

Oxidation of SO₂ was shown to occur in aqueous solutions of Li, Na, and K trifluoroacetates at room temperature. Oxidative activity of the non-transition metal trifluoroacetates increases on decreasing pH of solution and at equal pH values, it follows the sequence: Li < Na < K.     

Thiapyrylium trifluoroacetates and thiacyclohexanes from 1, 5-diketones

1,5-Diketones react with hydrogen sulfide and trifluoroacetic acid to give a mixture of thiapyrylium trifluoroacetates or sym-octahydrothiaxanthylium trifluoroacetates with thiacyclohexanes or perhydrothiaxanthenes, respectively.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 916–919, July, 1972.     

Ternary water-salt system Sm(CCl<Subscript>3</Subscript>COO)<Subscript>3</Subscript>-Er(CCl<Subscript>3</Subscript>COO)<Subscript>v</Subscript>-H<Subscript>2</Subscript>O at 298 K

The system of samarium and erbium trifluoroacetates and water has been studied by the isothermal solubility technique at 298 K. The composition of the solids has been determined using the Schreinemakers wet residue technique. The refractive indices, specific volumes, and viscosities of liquid phases and the refractive indices of solid residues have been determined. A continuous solid solution is found to form in the system. Some thermodynamic parameters have been determined for this solid solution.     

Palladium complex catalyzed acylation of allylic esters with acylstannanes: complementary method to the acylation with acylsilanes

Palladium-catalyzed acylation of allylic trifluoroacetates (2) using acylstannanes (1) is reported. The reaction serves as a complementary method to the previously reported acylation with acylsilane (4). In particular, the reaction is profitable in the acylation of unsubstituted allyl trifluoroacetate (2a) and benzoylation of allylic trifluoroacetates to afford synthetically useful beta,gamma-unsaturated ketones (3) in good yields without undesirable isomerizations.     

Luminescence of europium trifluoroacetates

The luminescence spectral characteristics of mixed-ligand europium trifluoroacetates with nitrogen- and phosphorus-containing neutral ligands were studied at different temperatures. For several trifluoroacetates, the intensity of luminescence increased with temperature. The diffuse reflectance data were analyzed, and a mechanism of thermal luminescence buildup was suggested. Original Russian Text ? I.V. Kalinovskaya, A.N. Zadorozhnaya, A.G. Mirochnik, V.E. Karasev, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 6, pp. 1175–1177.     

Thallium in organic synthesis. 63. A convenient synthesis of aromatic nitriles

Aromatic nitriles are readily formed by heating arylthallium bis(trifluoroacetates) with CuCN in acetonitrile.     

A new method for structure determination of trifluoroacetyl steroids by 19F-NMR

A useful method for the assignment of hydroxyl groups in steroids is described in which hydroxy-steroids are reacted with trifluoroacetic anhydride. The δ-values of the CF₃ signals from the resulting trifluoroacetates characterize the positions of the trifluoroacetylated hydroxyl groups.     

Pyrolytic synthesis and Eu→Eu reduction process of blue-emitting perovskite-type BaLiF3:Eu thin films

Perovskite-type barium lithium fluoride (BaLiF₃) was synthesized by pyrolysis of metal trifluoroacetates. The reaction temperature necessary for producing a single-phase material was found to be 600°C, which was lower than that for a conventional solid-state reaction or a melting method. Eu-doped BaLiF₃ was also prepared and characterized to examine the suitability of trifluoroacetates for precursors in synthesizing homogeneous complex metal fluoride materials. It was demonstrated that trivalent Eu³⁺, which was used as acetate for a starting material, was reduced to divalent Eu²⁺ in the pyrolysis process of BaLiF₃, as indicated by a broad blue emission due to an allowed 4f⁶5d→4f⁷ transition at 408 nm with a ultraviolet excitation at 254 nm. The concentration quenching of the blue emission occurred at 5 at% of Eu in BaLiF₃, indicating that Eu was homogeneously dispersed in the BaLiF₃ host lattice. Mechanisms of the formation and reduction process of BaLiF₃ were discussed based on pertinent chemical reactions.     

Variation in the sorption energy of esters ofn-perfluoroalkanoic acids on chromatographic phases of different polarity

The contributions of methylene and difluoromethylene units of six homologous and six pseudohomologous series of esters ofn-perfluoroalkanoic acids to the differential molar free energy, enthalpy, and entropy of sorption on stationary phases of different polarities in glass capillary columns under isothermal conditions were calculated. The features observed characterize the peculiarities of the sorption of esters of polyfluorinated carboxylic acids on phases of different polarities and make it possible to estimate the enthalpy and entropy contributions to the energy of sorption of the esters, the effect of the temperature of the analysis and the length of the alkyl or polyfluoroalkyl chain on the retention parameters of the compound analyzed. The inversion of the retention order of trifluoroacetates and pentafluoropropionates in XE-60 nitrile-containing phase was found.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2051–2055, December, 1993.     

Bis(B-carboranyl)thallium salts

Conclusions Borothallated carboranylthallium bis(trifluoroacetates) are converted to bis(B-carboranyl)thallium salts by treatment with AcONa or LiAlH₄.Translated from Izvestiya Akademii Nauk SSSR, Serlya Khimicheskaya, No. 6, pp. 1426–1428, June, 1981.     

The reactivity of organothallium compounds. Kinetics and mechanism of iodination of diarylthallium salts by molecular iodine in dioxane

The kinetics and mechanism of the reactions of diarylthallium, trifluoroacetates with molecular iodine in dioxane solutions have been studied. The reaction has the overall second order with the first order with respect to each reagent. The effect of substituents in the aromatic ring on the rate constant of iodination is described by the equation logk ₂ρσ⁺(ρ=-1.60, r=0.97). The reaction is catalyzed by the iodide ion. The activation enthalpies and entropies of iodination of diarylthallium trifluoroacetates in dioxane and di(p-anisyl)thallium trifluoroacetate in various solvents have been calculated. The effect of solvents on the rate constant of iodination of di(p-anisyl)thallium trifluoroacetate has been studied. The reaction mechanism is considered as an electrophilicS _EC process. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 451–455, March, 1999.     

Synthesis and antimicrobial activity of N-(indol-5-yl)trifluoroacetamides and indol-5-ylaminium trifluoroacetates substituted in the pyrrole ring

Russian Chemical Bulletin - Based on a series of 1H-indol-5-ylamines substituted in the pyrrole ring, the corresponding N-(indol-5-yl)trifluoroacetamides and indol-5-ylaminium trifluoroacetates...     

Indolopyridines with an angular heteroatom. 11. Synthesis of 12-arylidenindolo-[2,1-a]isoquinolinium salts

The condensation of aromatic aldehydes with indolo[2,1-a]isoquinoline in a solution of trifluoroacetic acid yielded a series of 12-arylidenindolo[2,1-a]isoquinolinium trifluoroacetates. Analogous quaternary salts are formed with trichloroacetic and acetic acids as well as upon the reaction of indoloisoquinolinium hydrochloride with p-nitrobenzaldehyde or with p-nitrophenyldiazonium chloride in ethanol.Russian Peoples Friendship University, 117198 Moscow, Russia Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 786–790, June, 1999.     

Catalytic enantioselective protonation of enol trifluoroacetates by means of hydrogenocarbonates and cinchona alkaloids

Herein is disclosed an efficient catalytic enantioselective protonation of enol acetates by means of a readily implementable transition-metal-free chemical process. By making use of simple hygrogenocarbonates as the proton source and hydroquinine anthraquinone-1,4-diyl diether as the chiral proton shuttle, a series of cyclic enol trifluoroacetates are protonated under mild conditions to yield the corresponding ketones in up to 93% ee.     

Synthesis of calcium, strontium, and barium fluorides by thermal decomposition of trifluoroacetates

Alkaline-metal (barium, strontium, and calcium) fluorides with a highly developed specific surface are synthesized by the thermal decomposition of the corresponding metal trifluoroacetates in an inert atmosphere followed by annealing in an oxygen flow at 500°C. The specific surfaces of the synthesized samples are studied by comparative nitrogen adsorption. The resulting specific surface values are 43.67, 36.52, and 23.98 m²/g for CaF₂, SrF₂, and BaF₂, respectively.     

Synthesis of C-29-phosphonium derivatives of 3,28-diacetoxylup-20(29)-en-30-oic acid

3β,28-Diacetoxylup-20(29)-en-30-oic acid (obtained via oxidation of betulin diacetate) enters the addition reaction with P—H-phosphonium salts (triarylphosphonium trifluoroacetates) under mild conditions to afford β-carboxyalkylphosphonium salts. Structure and composition of the resulting compounds were confirmed by NMR and IR spectroscopy, mass spectrometry, and elemental analysis.

     

Synthesis of trifluoromethyl-substituted heteroaromatic aldehydes

Trifluoromethylation of furfural and thiophene-2-carbaldehyde trifluoroacetates with XeF₂ and CF₃COOH afforded 5-trifluoromethylfuran-2-carbaldehyde and 5-trifluoromethylthiophene-2-carbaldehyde. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1623–1625, July, 2005.     

Synthesis of alkenes from tertiary esters utilizing the triphenylphosphine-iodine system

The treatment of tertiary esters with triphenylphosphine and iodine under mild conditions gives the most stable alkene in good yield. Formates, acetates and trifluoroacetates were studied.     

Facile synthesis of α,α-difluoroalkyl aryl thioethers and their oxidative desulfurization-fluorination to trifluorides

Alkyl 2-arylthio-2,2-difluoroacetates are synthesized in 52-77% yield from alkyl 2-(arylthio)acetates via two succeeding fluoro-Pummerer rearrangements using the reagents combination of N-haloimides as electrophiles and excess Py·9HF as the fluoride source at room temperature. Subsequent treatment of the formed fluorinated thioethers with the same reagents at elevated temperature gave alkyl trifluoroacetates in almost quantitative yield under optimised conditions by oxidative desulfurization-fluorination.     

Synthesis and some properties of 2,2-bis(difluoroamino)propanol

Conclusions Geminal bis(difluoroamino) alcohols were obtained by reacting difluoroamine with the trifluoroacetates of acetylenic alcohols and subsequent saponification. Some of the chemical properties of 2,2-bis(difluoroamino)-propanol were studied.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 458–460, February, 1982.