- REACTIVITE DES ESTERS SULFONIQUES ET PYROSULFONIQUES PERFLUORES RFSO3RF ET RFSO3SO3RF. HETEROLYSE DE LA LIAION S-O
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Perfluoroalkyl perfluoroalkanesulfonates RFSO3R'F (RF, R'F = CF3, C2F5) and perfluoroalkyl perfluoroalkanepyrosulfonates RFSO3SO3RF, mixed with perfluoroalkanesulfonic acids (CF3SO3H or C2F5SO3H) decompose thermally.Depending on the starting materials, different products result from nucleophilic attack of a perfluoroalkanesulfonate anion of the acid on the sulfur atom of the sulfonate group of the ester, with heterolysis of the S-O bond.Therefore, under these conditions, the perfluorinated esters are not perfloroalkylating agents, but rather perfluorosulfonylating agents.
- Oudrhiri-Hassani, M.,Brunel, D.,Germain, A
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Read Online
- The vibrational spectrum of trifluoromethanesulphonic acid, CF3SO3H, and the determination of its degrees of discociation in aqueous solution by Raman spectroscopy
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The Raman and i.r. spectra of trifluoromethanesulphonic acid, CF3SO3H, have been obtained, and vibrational assignments made which are consistent with Cs molecular symmetry.The degrees of dissociation of CF3SO3H in aqueous solution in the concentration range 1.8-11.1 M were determined from Raman intensity measurements on the Δν = 1034 cm-1 band characteristic of the CF3SO3- ion.The results confirm that CF3SO3H is more dissociated into CF3SO3- ions than CH3SO3H is into CH3SO3- at similar concentrations.A limiting value of Kc = 280 mol dm-3 is calculated for low acid concentrations of CF3SO3H.
- Edwards, H. G. M.
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- Perfluoroalkanesulfonylimids and their lithium salts: Synthesis and characterisation of intermediates and target compounds
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ECF processes have been extensively experienced and developed since early 1970s at the Fluorine Chemistry Laboratory of Padua University: several classes of perfluorinated inert and functional compounds have been obtained, in particular perfluoro heterocyclics and perfluorinated acid fluorides.Recently the demand for electrolyte salts, applied in lithium batteries, drove our interest to investigate on the perfluoroalkanesulfonylimides.A series of the perfluoroalkanesulfonylfluoride precursors has been obtained by ECF and their metathesis to the related imides and lithium salts has been investigated.A number of representative products has been obtained and characterized in their structure and ionic conductivity.
- Conte, Lino,Gambaretto, Gian Paolo,Caporiccio, Gerardo,Alessandrini, Fabrizio,Passerini, Stefano
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- Thermodynamics of methanesulfonic acid revisited
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Recently we reported a study of the thermodynamics of methanesulfonic acid and some of its derivatives. The foundation of these results was a measurement of the heat of reaction of S-methyl thioacetate with aq sodium hypochlorite, leading to methanesulfonic acid. We have reinvestigated this reaction and discovered that contrary to the initial stoichiometry experiments, the stoichiometry under the reaction conditions is not as was believed and that the heat of reaction observed was spuriously high. We have found a new reaction, that of sulfite ion with methyl methanesulfonate, which does allow a clean determination of the heat of formation of methanesulfonic acid. Revised thermodynamic quantities for methanesulfonic acid, methanesulfonyl chloride, and methyl methanesulfonate are reported here.
- Guthrie,Gallant
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- Photoinduced and Thermally Induced Rearrangements in a Thianthrenium Salt System
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A low-lying ?* level localized on a sulphur-carbon moiety in p-cyanobenzylthianthrenium trifluoromethanesulphonate allows facile photoinduced molecular rearrangements to occur via an in-cage fragmentation-recombination mechanism involving cation-radical-radical intermediates.
- Saeva, Franklin D.
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- SYNTHESIS OF TRIFLUOROMETHANESULFONATE ESTERS BY REATION OF ALKYL CHLORIDES WITH CHLORINE (I) AND BROMINE (I) TRIFLUOROMETHANESULFONATE
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The synthesis of the first trifluoromethanesulfonate esters of the type CF3SO3(CH2)nO3SCF3(n=1,2,3) are reported.The new compounds are prepared from Cl(CH2)nCl by substitutive electrophilic dehalogenation reactions with CF3SO2OX (x=Cl,Br).The extension of this reaction to HCCl3 results in HC(O3SCF3)3 but the compound is unstable at 22 deg.
- Katsuhara,Yutaka,Desmarteau, Darryl D.
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- Remarkable Acid Catalysis in Proton-Coupled Electron-Transfer Reactions of a Chromium(III)-Superoxo Complex
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Much enhanced acid catalysis was observed in oxygen atom transfer (OAT) reactions by a mononuclear nonheme Cr(III)-superoxo complex, [(Cl)(TMC)CrIII(O2)]+ (1), in the presence of triflic acid. In the acid-catalyzed reactions, the reactivity of 1 in OAT of thioanisole was enhanced significantly, showing more than 104-fold acceleration in rate. Electron transfer (ET) from electron donors to 1 also occurred only in the presence of HOTf. The enhanced reactivity of 1 by HOTf was explained by proton-coupled electron transfer from electron donors, such as ferrocene, to 1 in light of the Marcus theory of ET. The present study reports for the first time the dramatic proton effect on the chemical properties of metal-superoxo species.
- Devi, Tarali,Lee, Yong-Min,Nam, Wonwoo,Fukuzumi, Shunichi
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- Synthesis of trifluoromethanesulfonic acid from CHF3
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Trifluoromethane is transformed to trifluoromethanesulfonic acid (TFMSA) at low temperature in a liquid-phase reaction in a strong acid such as fuming sulfuric acid as well as in a strong basic solution such as t-BuOK/DMF.
- Mukhopadhyay, Sudip,Bell, Alexis T.,Vijay Srinivas,Smith, Gary S.
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- PROCESS FOR THE PREPARATION OF HALOALKANESULFONIC ACIDS FROM SULFUR TRIOXIDE AND A HALOALKANE
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The present invention relates to a process for preparing haloalkanesulfonic acids from sulfur trioxide and a haloalkane, particularly to a process for preparing trifluoromethane sulfonic acid from sulfur trioxide and trifluoromethane.
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Page/Page column 16; 17
(2019/12/15)
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- Water determines the products: An unexpected Br?nsted acid-catalyzed PO-R cleavage of P(iii) esters selectively producing P(O)-H and P(O)-R compounds
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Water is found able to determine the selectivity of Br?nsted acid-catalyzed C-O cleavage reactions of trialkyl phosphites: with water, the reaction quickly takes place at room temperature to afford quantitative yields of H-phosphonates; without water, the reaction selectively affords alkylphosphonates in high yields, providing a novel halide-free alternative to the famous Michaelis-Arbuzov reaction. This method is general as it can be readily extended to phosphonites and phosphinites and a large scale reaction with much lower loading of the catalyst, enabling a simple, efficient, and practical preparation of the corresponding organophosphorus compounds. Experimental findings in control reactions and substrate extension as well as preliminary theoretical calculation of the possible transition states all suggest that the monomolecular mechanism is preferred.
- Li, Chunya,Wang, Qi,Zhang, Jian-Qiu,Ye, Jingjing,Xie, Ju,Xu, Qing,Han, Li-Biao
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supporting information
p. 2916 - 2922
(2019/06/18)
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- METHOD FOR PREPARING OXYSULPHIDE AND FLUORINATED DERIVATIVES IN THE PRESENCE OF AN ORGANIC SOLVENT
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The present invention concerns a method for preparing an oxysulphide and fluorinated derivative of formula (III) Ea-SO3R (III) that comprises bringing a compound of formula (II) Ea-SOOR (II)—Ea representing the fluorine atom or a group having 1 to 10 carbon atoms chosen from the fluoroalkyls, the perfluoroalkyls and the fluoroalkenyls; and—R representing hydrogen, a monovalent cation or an alkyl group; into contact, in the presence of a polar aprotic organic solvent, with an oxidising agent.
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Paragraph 0193-0195
(2019/04/05)
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- Dicationic Thiolate-Bridged Diruthenium Complexes for Catalytic Oxidation of Molecular Dihydrogen
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Dicationic thiolate-bridged diruthenium complexes bearing sterically bulky alkane substituents on the thiolate ligands such as [Cp?Ru(μ-SiPr)2Ru(OH2)Cp?](OTf)2 have been found to work as effective catalysts toward oxidation of molecular dihydrogen into protons and electrons in protic solvents such as water and methanol. DFT calculations indicate that the sterically bulky alkane substituent in the complex plays an important role in facilitating the reaction step of the coordination of molecular dihydrogen.
- Yuki, Masahiro,Sakata, Ken,Nakajima, Kazunari,Kikuchi, Syoma,Sekine, Shinobu,Kawai, Hiroyuki,Nishibayashi, Yoshiaki
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supporting information
p. 4499 - 4506
(2017/12/05)
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- Total synthesis and stereochemical assignment of nostosin B
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Nostosins A and B were isolated from a hydrophilic extract of Nostoc sp. strain from Iran, which exhibits excellent trypsin inhibitory activity. Nostosin A was the most potent natural tripeptide aldehyde as trypsin inhibitor up to now. Both R- and S-2-hydroxy-4-(4-hydroxy-phenyl)butanoic acid (Hhpba) were prepared and incorporated into the total synthesis of nostosin B, respectively. Careful comparison of the NMR spectra and optical rotation data of synthetic nostosin B (1a and 1b) with the natural product led to the unambiguous identification of the R-configuration of the Hhpba fragment, which was further confirmed by co-injection with the authentic sample on HPLC using both reversed phase column and the chiral AD-RH column.
- Wang, Xiaoji,Feng, Junmin,Xu, Zhengshuang,Ye, Tao,Meng, Yi,Zhang, Zhiyu
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- Catalytic Activity of Thiolate-Bridged Diruthenium Complexes Bearing Pendent Ether Moieties in the Oxidation of Molecular Dihydrogen
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Thiolate-bridged diruthenium complexes bearing pendent ethers have been found to work as effective catalysts toward the oxidation of molecular dihydrogen into protons and electrons in water. The pendent ether moiety in the complex plays an important role to facilitate the proton transfer between the metal center and the external proton acceptor.
- Yuki, Masahiro,Sakata, Ken,Kikuchi, Shoma,Kawai, Hiroyuki,Takahashi, Tsuyoshi,Ando, Masaki,Nakajima, Kazunari,Nishibayashi, Yoshiaki
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supporting information
p. 1007 - 1012
(2017/02/05)
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- A process for the preparation of triflic acid
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The invention relates to a trifluoromethanesulfonic acid preparation method. The method includes: taking halogenated trifluoromethane as a raw material, adding zinc powder and terahydrofuran under the environment of nitrogen protection and feeding trifluoro bromomethane gas prior to adding catalytic amount to obtain lodine; obtaining trifluoromethyl zinc halide through temperature control reaction, adding sulfur trioxide for continuous reaction to generate halogenated trifluoromethane sulfonic acid zinc; adding reaction liquid into alkali liquid for neutralization, evaporating filter liquid to dryness to obtain solid sodium trifluoromethanesulfonate salt prior to acidizing and rectifying to obtain trifluoromethanesulfonia acid. With the method, generation of accessory substances during the production is effectively reduced; the situation about higher fluorinion, chloridion and sulfate ion in trifluoromethanesulfonia acid products in a traditional technology is avoided. In addition, the purity of the trifluoromethanesulfonia acid obtained from distillation and purification can reach 99.95% above, and the yield can reach 83%.
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Paragraph 0030; 0031
(2018/01/19)
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- Study of the Paternò–Büchi type photolabile protecting group and application to various acids
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An efficient photolabile protecting group, thiochromone S,S-dioxides with the diazomethyl group for phosphate derivatives, amino acids and sulfonic acids was developed. Protection and photodeprotection reactions proceeded smoothly under mild conditions without any catalyst.1H NMR and HPLC spectra studies demonstrated the photolysis properties of the photolabile protecting group and gave an exact quantification of the released substrates. Specially, the photoproduct derived from the thiochromone derivatives following Paternò–Büchi type photo-cycloaddition showed high fluorescence intensity. This fluorescent characteristic demonstrated the photodeprotection progress also can be monitored by fluorescence spectra.
- Zhang, Youlai,Zhang, Huan,Ma, Chi,Li, Junru,Nishiyama, Yasuhiro,Tanimoto, Hiroki,Morimoto, Tsumoru,Kakiuchi, Kiyomi
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supporting information
p. 5179 - 5184
(2016/11/13)
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- Preparation method of trifluoromethane sulfonic acid
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The invention relates to a preparation method of trifluoromethane sulfonic acid. According to the preparation method, trifluoromethanesulphonyl fluoride and alkali metal hydroxide are subjected to a neutralizing hydrolysis reaction under existence of a fluorine fixing agent, after the reaction is completed, reaction liquid is filtered and dried, and fluorinated methyl sulfonic acid alkali metal salt is obtained; the fluorinated methyl sulfonic acid alkali metal salt and fuming sulphuric acid are subjected to acidizing treatment, then rectification is conducted multiple times, and high-purity trifluoromethane sulfonic acid is obtained. Through improvement of the preparation method, operating flexibility, production efficiency and product stability are improved, the comprehensive yield is raised, product purity can reach 99.90% or above, and the preparation method is suitable for industrial production.
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Paragraph 0023; 0025; 0027; 0035
(2017/01/09)
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- HYDROGEN OXIDATION CATALYST
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The present invention is to provide a hydrogen oxidation catalyst that does not contain platinum. Disclosed is a hydrogen oxidation catalyst that is a dinuclear transition metal complex having a chemical structure represented by the following general formula (1) or (2): wherein, in the general formulae (1) and (2), M1 and M2 are each independently Fe or Ru; Ar1 and Ar2 are each independently a cyclopentadienyl group or a pentamethylcyclopentadienyl group; Ar3 and Ar4 are each independently a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms; and Ar5 is a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, and in the general formula (2), R1 and R2 are each independently a hydrogen atom or a monovalent aliphatic hydrocarbon group having 1 to 3 carbon atoms.
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Paragraph 0050
(2017/01/09)
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- METHOD FOR PREPARING A SULFONIMIDE COMPOUND AND SALTS THEREOF
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The present invention relates to a method for preparing an aqueous sulfonimide compound of the formula (Rf1—SO2) (Rf2—SO2)NH, wherein Rf1et Rf2 are independently selected from the group comprising: a fluorine atom and groups having 1 to 10 carbon atoms selected from the perfluoroalkyl, fluoroalkyl, fluoroalkenyl and fluoroallyl groups, from a mixture M1 including (Rf1—SO2)(Rf2—SO2)NH, Rf1SO2H and/or Rf2SO2H, Rf1SO2NH2 and/or Rf2SO2NH2, characterized in that said method includes an oxidation step of said mixture M1 using an oxidizing agent in order to obtain a mixture M2 including (Rf1—SO2)(Rf2—SO2)NH, Rf1SO3H and/or Rf2SO3H, and Rf1SO2NH2 and/or Rf2SO2NH2.
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Paragraph 0365; 0366
(2015/07/27)
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- Thiolate-bridged dinuclear ruthenium and iron complexes as robust and efficient catalysts toward oxidation of molecular dihydrogen in protic solvents
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Thiolate-bridged dinuclear ruthenium and iron complexes are found to work as efficient catalysts toward oxidation of molecular dihydrogen in protic solvents such as water and methanol under ambient reaction conditions. Heterolytic cleavage of the coordinated molecular dihydrogen at the dinuclear complexes and the sequential oxidation of the produced hydride complexes are involved as key steps to promote the present catalytic reaction. The catalytic activity of the dinuclear complexes toward the chemical oxidation of molecular dihydrogen achieves up to 10000 TON (turnover number), and electrooxidation of molecular dihydrogen proceeds quite rapidly. The result of the density functional theory (DFT) calculation on the reaction pathway indicates that a synergistic effect between the two ruthenium atoms plays an important role to realize the catalytic oxidation of molecular dihydrogen efficiently. The present dinuclear ruthenium complex is found to work as an efficient organometallic anode catalyst for the fuel cell. It is noteworthy that the present dinuclear complex worked not only as an effective catalyst toward chemical and electrochemical oxidation of molecular dihydrogen but also as a good anode catalyst for the fuel cell. We consider that the result described in this paper provides useful and valuable information to develop highly efficient and low-cost transition metal complexes as anode catalysts in the fuel cell.
- Yuki, Masahiro,Sakata, Ken,Hirao, Yoshifumi,Nonoyama, Nobuaki,Nakajima, Kazunari,Nishibayashi, Yoshiaki
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supporting information
p. 4173 - 4182
(2015/04/14)
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- PHOTOELECTRIC CONVERSION ELEMENT, DYE-SENSITIZED SOLAR CELL, METAL COMPLEX DYE, DYE SOLUTION, DYE-ADSORBED ELECTRODE, AND METHOD FOR PRODUCING DYE-SENSITIZED SOLAR CELL
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A photoelectric conversion element, having a photoconductor layercontaining semiconductor fine particles carrying a metal complex dye of Formula (I); a metal complex dye, a dye solution, a dye-adsorbed electrode, a dye-sensitized solar cell, and a method for producing the solar cell: M(LA)(LD)(LX)mX·(CI)mY??Formula (I) M represents a metal ion, LA represents a ligand of Formula (AL), LD represents a bidentate or tridentate ligand, at least one of coordinating atoms being an anion; LX represents a monodentate ligand; CI represents a counter ion; mX is 0 or 1; mY is 0 to 3; Rings A to C represent a heterocycle; Z1 and Z2 represent a carbon or nitrogen atom; Anc1 to Anc3 represent an acidic group; X1 to X3 represent a single bond or linking group; R1 to R3 represent a substituent; l1, l3, l2, m1, m3, m2, n1, n2, and n3 each are an integer.
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- DIRECT TRIFLUOROMETHYLATIONS USING TRIFLUOROMETHANE
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A direct trifluoromethylation method preferably using a trifluoromethane as a fluoro-methylating species. In particular, the present method is used for preparing a trifluoromethylated substrate by reacting a fluoromethylatable substrate with a trifiuoromethylating agent in the presence of an alkoxide or metal salt of silazane under conditions sufficient to trifluoromethylate the substrate; wherein the fluoromethylatable substrate includes chlorosilanes, carbonyl compounds such as esters, aryl halides, aldehydes, ketones, chalcones, alkyl formates, alkyl halides, aryl halides, alkyl borates, carbon dioxide or sulfur.
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Paragraph 0080
(2014/03/25)
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- FLUOROALKANESULFONIC ACID PRODUCTION METHOD
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Disclosed is a method for producing a fluoroalkanesulfonic acid including (1) the step of reacting concentrated sulfuric acid and/or fuming sulfuric acid with a fluoroalkanesulfonate to cause an acid decomposition, thereby obtaining a reaction mixture containing the fluoroalkanesulfonic acid and a sulfur component; and (2) the step of adding an oxidizing agent to the reaction mixture obtained by the above step and then conducting a distillation, thereby obtaining the fluoroalkanesulfonic acid from the reaction mixture. It is possible by this method to efficiently reduce the sulfur component, thereby industrially advantageously obtaining fluoroalkanesulfonic acid of high purity.
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Paragraph 0047; 0052
(2014/06/24)
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- Copper mediated stereoselective synthesis of C-glycosides from unactivated alkynes
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A highly stereoselective rapid C-glycosylation reaction has been developed between glycal and unactivated alkynes in the presence of coppertriflate and ascorbic acid at low catalyst loading and at room temperature. A wide variety of glycals and aryl acetylenes participate in the reaction smoothly. TfOH generated during the reduction of Cu(OTf)2 by ascorbic acid may be the active catalyst for the glycosylation. The Royal Society of Chemistry 2013.
- Kusunuru, Anil Kumar,Tatina, Madhubabu,Yousuf, Syed Khalid,Mukherjee, Debaraj
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supporting information
p. 10154 - 10156
(2013/10/22)
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- Synthesis and reactivity studies of dicationic dihydrogen complexes bearing sulfur-donor ligands: A combined experimental and computational study
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A series of dihydrogen complexes trans-[Ru(η2-H 2){SC(SR)H}(dppe)2][X][BF4] (R = CH 3, X = OTf; R = C6H5CH2, X = BPh4; R = H2C=CHCH2, X = BPh4; dppe = Ph2PCH2CH2PPh2) bearing sulfur-donor ligands has been synthesized by protonation of the (alkyl dithioformate)hydrido complexes trans-[Ru(H){SC(SR)H}(dppe)2][X] by using HBF4·Et2O. Competitive substitution reactions between H2 and SC(SR)H in trans-[Ru(η2-H 2){SC(SR)H}(dppe)2][X][BF4] have been studied by treatment with CH3CN, CO, and P(OCH3)3. These resulted in the expulsion of SC(SR)H from the metal center, thus indicating that the alkyl dithioformate ligand is more labile than H 2. Bonding of alkyl dithioformate ligands (sulfur-donor ligands) trans to H2 have been studied by comparing the H-H distances and chemical-shift values (1H NMR spectroscopy) of the various dihydrogen complexes bearing different trans ligands. This study qualitatively suggests that the alkyl dithioformate ligands in these trans-dihydrogen complexes show a poor π effect, and it is further supported by density functional theory calculations. The first example of a dihydrogen complex bearing dithioformic acid, trans-[Ru(η2-H2){SC(SH)H}(dppe) 2][BF4]2, was obtained by protonation of trans-[Ru(H){SC(S)H}(dppe)2] by using HBF4·Et 2O. Copyright
- Gandhi, Thirumanavelan,Rajkumar, Subramani,Prathyusha,Priyakumar, U. Deva
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p. 1434 - 1443
(2013/05/22)
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- Taming of fluoroform: Direct nucleophilic trifluoromethylation of Si, B, S, and C centers
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Fluoroform (CF3H), a large-volume by-product of the manufacture of Teflon, refrigerants, polyvinylidene fluoride (PVDF), fire-extinguishing agents, and foams, is a potent and stable greenhouse gas that has found little practical use despite the growing importance of trifluoromethyl (CF3) functionality in more structurally elaborate pharmaceuticals, agrochemicals, and materials. Direct nucleophilic trifluoromethylation using CF3H has been a challenge. Here, we report on a direct trifluoromethylation protocol using close to stoichiometric amounts of CF3H in common organic solvents such as tetrahydrofuran (THF), diethyl ether, and toluene. The methodology is widely applicable to a variety of silicon, boron, and sulfur-based electrophiles, as well as carbon-based electrophiles.
- Surya Prakash,Jog, Parag V.,Batamack, Patrice T. D.,Olah, George A.
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p. 1324 - 1327
(2013/02/22)
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- Reactions of N-aryl(methyl, trifluoromethyl)sulfonyl-1,4-benzoquinone monoimines with sodium sulfi nates
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In reactions with sodium sulfi nates of N-substituted 1,4-benzoquinone monoimines with the quinoid ring having free positions 2 and/or 6 the fraction of products of 1,4-addition of the sulfi nate ion grows in the series ArSO 2 → MeSO2 → CF3SO2. In the case of 2,6-dimethyl derivatives the 1,6-addition is preferable, and the amount of products of 6,1-addition decreases. Pleiades Publishing, Ltd., 2012.
- Avdeenko,Konovalova,Mikhailichenko,Shelyazhenko,Pirozhenko,Yagupol'Skii
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experimental part
p. 221 - 233
(2012/06/04)
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- A PROCESS FOR THE MANUFACTURE OF TRIFLIC ACID
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The present invention relates to a process for the preparation of triflic acid by chloroxidation.
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Page/Page column 11-12
(2011/09/30)
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- NOVEL POLYMERIZABLE MONOMER, AND MATERIAL FOR ORGANIC DEVICE, HOLE INJECTION/TRANSPORT MATERIAL, MATERIAL FOR ORGANIC ELECTROLUMINESCENT ELEMENT AND ORGANIC ELECTROLUMINESCENT ELEMENT EACH COMPRISING POLYMER (POLYMERIC COMPOUND) OF THE POLYMERIZABLE MONOMER
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A polymerizable monomer represented by the following formula (1) wherein at least one of Ar1 to Ar3 is substituted by a group represented by the following formula (2) and which is substituted by one or more groups comprising a polymerizable functional group. Ar1 to Ar3 are a substituted or unsubstituted aryl group having 6 to 40 ring carbon atoms, Ar6 is a substituted or unsubstituted aryl group having 6 to 40 ring carbon atoms and Ar4 and Ar5 are a substituted or unsubstituted arylene group having 6 to 40 ring carbon atoms.
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- Hidden Bronsted acid catalysis: Pathways of accidental or deliberate generation of triflic acid from metal triflates
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The generation of a hidden Bronsted acid as a true catalytic species in hydroalkoxylation reactions from metal precatalysts has been clarified in case studies. The mechanism of triflic acid (CF3SO3H or HOTf) generation starting either from AgOTf in 1,2-dichloroethane (DCE) or from a Cp*RuCl2/AgOTf/phosphane combination in toluene has been elucidated. The deliberate and controlled generation of HOTf from AgOTf and cocatalytic amounts of tert-butyl chloride in the cold or from AgOTf in DCE at elevated temperatures results in a hidden Bronsted acid catalyst useful for mechanistic control experiments or for synthetic applications.
- Dang, Tuan Thanh,Boeck, Florian,Hintermann, Lukas
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experimental part
p. 9353 - 9361
(2012/01/04)
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- Cationic and radical intermediates in the acid photorelease from aryl sulfonates and phosphates
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The irradiation of a series of phenyl sulfonates and phosphates leads to the quantitative release of acidity with a reasonable quantum yield (≈0.2). Products characterization, ion chromatography analysis and potentiometric titration are consistent with the intervening of two different paths in this reaction, viz. cationic with phosphates and (mainly) radical with sulfonates. The Royal Society of Chemistry and Owner Societies 2011.
- Terpolilli, Marco,Merli, Daniele,Protti, Stefano,Dichiarante, Valentina,Fagnoni, Maurizio,Albini, Angelo
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experimental part
p. 123 - 127
(2012/01/03)
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- Alkynes to (E)-enolates using tandem catalysis: Stereoselective anti-aldol and syn-[3,3]-rearrangement reactions
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A new tandem catalysis strategy that transforms alkyne derivatives to (E)-enol-equivalents followed by stereoselective anti-selective aldol coupling or syn-selective [3,3]-rearrangement transformations is reported. The mechanism is thought to proceed through an interchanging series of Lewis acid and Bronsted acid catalyzed reactions via the intermediacy of a ketiminum ion species.
- Grimster, Neil P.,Wilton, Donna A.A.,Chan, Louis K.M.,Godfrey, Christopher R.A.,Green, Clive,Owen, Dafydd R.,Gaunt, Matthew J.
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experimental part
p. 6429 - 6436
(2010/10/19)
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- New electrophilic difluoromethylating reagent
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A new electrophilic difluoromethylating reagent has been developed. The S-(difluoromethyl)diarylsulfonium tetrafluoroborate has been shown to be effective for the introduction of an electrophilic difluoromethyl group into the following nucleophiles: sulfonic acids, tertiary amines, imidazole derivatives, and phosphines. The reagent failed to transfer the difluoromethyl group to phenols, carbon nucleophiles, and primary and secondary amines.
- Surya Prakash,Weber, Csaba,Chacko, Sujith,Olah, George A.
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p. 1863 - 1866
(2008/02/04)
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- Ion-detecting sensors comprising plasticizer-free copolymers
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Ion-detecting sensors for detecting a target ion in a sample are provided. The sensor comprises a plasticizer-free copolymer comprised of polymerized units of methacrylate monomers having pendent alkyl groups of different length and a functionalized ionophore of said ion, wherein at least a portion of the functionalized ionophore is grafted into the copolymer through covalent linkages. Sensors may comprise ionophores such as hydrophilic crown ethers or functionalized derivative of 3-oxapentandiaminde-type ionophores. This invention further provides sensors for detecting target ions in a sample, comprising plasticizer-free molecularly imprinted polymers, wherein the polymers comprise polymerized units of methacrylate monomers having pendent alkyl groups of different length and a functionalized ionophore of said ion. In particular, a magnesium ion sensor comprising a functionalized derivative of a 3-oxapentandiaminde-type calcium ion-selective ionophore is provided. Sensors of this invention include carrier-based ion-selective electrodes or optodes such as thin film ion-specific optodes, particle-based optodes, or bulk optodes.
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- Electrochemically stable onium salts and electrolytes containing such for electrochemical capacitors
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Based on the discovery that the melting point and solubility of onium salts are affected by the asymmetry of the substitution on cation, and that the branched substituents effectively shield onium cations from electrochemical reduction, new onium salts are synthesized and high performance electrolytes based on these salts for electrochemical capacitor are provided. The composition of the new electrolyte comprises an onium salt or mixture of such onium salts dissolved in aprotic, non-aqueous solvents or mixture of such solvents. The electrolyte is able to perform at high rate of charge/discharge, at low ambient temperatures, and within wide operating voltage, due to the high solubility, low melting temperature, and the improved reduction stability of the new onium cations, respectively.
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Page column 8
(2008/06/13)
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- 3-Alkylated-5,5',6,6',7,7,'8,8'-octahydro-2,2'-binaphthols and 3,3'-dialkylated-5,5',6,6',7,7',8,8'-octahydro-2,2'-binaphthols and processes for making them
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The compositions 3-alkylated-5,5′,6,6′,7,7′,8,8′-octahydro-2,2′-binaphthol and 3,3′-dialkylated-5,5′,6,6′,7,7′,8,8′-octahydro-2,2′-binaphthol are disclosed, as well as various processes for making them, all involving the alkylation of 5,5′,6,6′,7,7′,8,8′-octahydro-2,2′-binaphthol.
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- REAGENT AND PROCESS WHICH ARE USEFUL FOR GRAFTING A SUBSTITUTED DIFLUOROMETHYL GROUP ONTO A COMPOUND CONTAINING AT LEAST ONE ELECTROPHILIC FUNCTION
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The invention relates to a nucleophilic reagent which is useful for grafting a substituted difluoromethyl group onto a compound containing at least one electrophilic function, or for the synthesis of oxysulphide-containing and fluorine-containing organic derivatives, wherein said reagent comprises: a) a fluorocarboxylic acid of formula Ew—CF2—COOH where Ew represents an electron-withdrawing atom or group, at least partially salified with an organic or inorganic cation, and b) a polar aprotic solvent; and in that the content of releasable protons carried by its various components, including their impurities, is at most equal to half the initial molar concentration of the said fluorocarboxylic acid. A synthetic process uses this reagent by heating in order to graft a substituted difluoromethyl group onto various compounds.
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- Reagent and process which are useful for grafting a substituted difluoromethyl group onto a compound containing at least one electrophilic function
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The invention relates to a nucleophilic reagent which is useful for grafting a substituted difluoromethyl group onto a compound containing at least one electrophilic function, or for the synthesis of oxysulphide-containing and fluorine-containing organic derivatives, wherein said reagent comprises: a) a fluorocarboxylic acid of formula Ew—CF2—COOH where Ew represents an electron-withdrawing atom or group, at least partially salified with an organic or inorganic cation, and b) a polar aprotic solvent; and in that the content of releasable protons carried by its various components, including their impurities, is at most equal to half the initial molar concentration of the said fluorocarboxylic acid. A synthetic process uses this reagent by heating in order to graft a substituted difluoromethyl group onto various compounds.
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- Pharmaceutical compositions comprising metal complexes
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A compound of the formula [Ma(XbL)cYdZe]nt±Formula I wherein: M is a metal ion or a mixture of metal ions; X is a cation or a mixture of cations; L is a ligand, or mixture of ligands each containing at least two different donor atoms selected from the elements of Group IV, Group V or Group VI of the Periodic Table; Y is a ligand or a mixture of the same or different ligands each containing at least one donor atom or more than one donor atom selected from the elements of Group IV, Group V or Group VI of the Periodic Table; and Z is a halide or pseudohalide ion or a mixture of halide ions and pseudohalide ions; and wherein: a=1-3; b=0-12; c=0-18; d=0-18; e=0-18; and n=0-10; provided that at least one of c, d and e is 1 or more; wherein c is 0: b is also 0; wherein a is 1: c, d and e are not greater than 9; and wherein a is 2: c, d and e are not greater than 12.
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- Syntheses of new isodethiaazacephems and isodethiaazacephams, and use as potent antibacterial agents
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An isodethiaazacephem derivative having the following formula (I): wherein RIis hydrogen or —SO2RIII; RIIis —CO2RIVor —SO2RIIIin which RIIIis a hydrogen, C1-C6 alkyl, aralkyl having a total carbon number of 7-12, aryl, or a halogenated C1-C6 alkyl; and RIVis a hydrogen, C1-C6 alkyl, aralkyl having a total carbon number of 7-12 or aryl; and RVis a substituted acetamido radical.
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Page column 3
(2008/06/13)
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- Method for preparation of perfluoroalcanecarboxylic and perfluoroalkanesulfonic acids
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PCT No. PCT/FR96/02079 Sec. 371 Date Sep. 4, 1998 Sec. 102(e) Date Sep. 4, 1998 PCT Filed Dec. 24, 1996 PCT Pub. No. WO97/24309 PCT Pub. Date Jul. 10, 1997The invention consists of a new method for preparing perfluoroalcanecarboxylic and perfluoroalcanesulfonic acids in which ozone is made to react, in a protic environment, upon a perfluoroalkyl chain comprising at least one oxydizable chemical group.
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- Triazolo [4,5-d]pyrimidine compounds, their use as medicaments, compositions containing them and processes for their preparation
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PCT No. PCT/SE98/01392 Sec. 371 Date Sep. 30, 1998 Sec. 102(e) Date Sep. 30, 1998 PCT Filed Jul. 15, 1998 PCT Pub. No. WO99/05142 PCT Pub. Date Feb. 4, 1999The invention provides new triazolo[4,5-d]pyrimidine compounds, their use as medicaments, compositions containing them and processes for their preparation.
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- Solid aliphatic alkylation catalyst
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The invention concerns a catalyst comprising a porous organic or inorganic support and at least one active phase comprising at least one acid selected from acids with formula R--SO3 H, where R is fluorine or an alkyl group or a fluorinated alkyl group, and at least one weakly basic aprotic organic solvent, the support having been impregnated with the active phase, the catalyst being such that it is essentially constituted by particles with an average diameter in the range 0.1 μm to 150 μm, and being such that before impregnation with the active phase, the support has a total pore volume in the range 0.5 cm3 /g to 6 cm3 /g. The invention also concerns the use of the catalyst for aliphatic alkylation.
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- A new synthesis of azetidin-2-ones
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Diphosphonium trifluoromethanesulfonate Ph3P+-O-P+Ph3.2SO3CF3- readily brings about direct annelation of imines to substituted azetidin-2- ones.
- Bari,Sethi,Sharma, Ashok K.
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p. 1121 - 1122
(2007/10/03)
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- Process for producing 2-methyl-1,4-naphthoquinone
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The present invention provides a process for producing 2-methyl-1,4-naphthoquinone characterized by reaction between 2-methylnaphthalene and hydrogen peroxide and/or an organic peracid in a solvent comprising a carboxylic acid in the presence of a palladium compound and sulfuric acid.
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- Process for preparing alpha-amino-phenylacetic acid-trifluoromethane sulfonic acid mixed anhydrides
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A process is disclosed for the preparation of a compound of the Formula (VI) STR1 wherein X is a hydrogen atom, or OH, Y is a hydrogen atom, OH or a methyl group, R2 is a CH--COOR group, or a group of the formula (XI) STR2 and R is a C1 to C2 alkyl group, which comprises the step of: reacting a condensed salt of the Formula (IV) STR3 wherein Me is Na+ or K+, with a reactive derivative of trifluoromethane-sulfonic acid of the Formula (V) The compounds of the Formula (VI) are intermediates in the preparation of penicillins and cephalosporins with antibiotic activity.
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- One step synthesis of methyl t-butyl ether from t-butanol using fluorosulfonic acid-modified zeolite catalysts
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A method is disclosed wherein t-butanol is reacted with methanol in a reaction zone in one step to provide methyl tert-butyl ether and the improvement of accomplishing the reaction which comprises: a. Using a catalyst consisting of a crystalline aluminosilicate faujasite Y-type zeolite which has been treated with a fluorosulfonic acid; b. continuously contacting said t-butanol and methanol in a molar amount of about 0.1 to 10 moles of methanol per mole of t-butanol with said catalyst at a temperature of about 20° C. to about 250° C. and a pressure of about atmospheric to about 1000 psig to obtain the methyl tert-butyl ether product.
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- N-Fluorobisimides: Reactions with Some Olefins via α-Fluoro Carbocationic Intermediates
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N-Fluorobisimides are a new class of electrophilic fluorinating agents.Reaction of (CF3SO2)2NF (1) with olefins gave various products, depending on the reaction conditions and the structure of the substrate.In solvents of higher nucleophilicity such as H2O, acetic acid, aqueous HCl, and (HF)nPy, α-fluorohydrins and their acetates, α,β-chlorofluoro- and α,β-difluoroalkanes were obtained.In acetic acid, trans-stilbene and tetraphenylethylene produced the rearranged, nonfluorinated aldehyde and ketone.Evidence is presented for the reactions proceeding via a one-electron transfer mechanism involving α-fluorocarbocationic intermediates.
- DesMarteau, Darryl D.,Xu, Ze-Qi,Witz, Michael
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p. 629 - 635
(2007/10/02)
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- Process for the preparation of trifluoromethanesulphonic acid
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Trifluoromethanesulphonic acid is prepared from bis-(trifluoromethyl) disulphane in the liquid phase and in acidic medium by means of an oxygen-containing oxidizing agent.
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- Process for the preparation of halogen-containing aromatic compounds
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A process for the preparation of halogen-containing aromatic compounds of the formula STR1 wherein Hal represents fluorine, chlorine or bromine and Z represents an aromatic group which comprises reacting a halobenzene of the formula C6 H5 Hal (II) under anhydrous conditions with a halide of a bisacid having the formula Hal-CO-Z-CO-Hal (III) in a molar ratio of at least 2:1 in the presence of a haloalkane sulfonic acid of the formula Y(Cn X2n)SO3 H (IV), in formulae II and III Hal and Z having the afore-mentioned meaning and Y representing fluorine or hydrogen, X at least one of fluorine and chlorine, but at least one X being fluorine, and n being an integer of from 1 to 10. The said bis-(4-halobenzoyl) compounds being useful monomers for chemically resistant plastics which are still resistant even at high temperatures.
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- Photochemistry of triarylsulfonium salts
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The photolysis of triphenylsulfonium, tris(4-methylphenyl)sulfonium, tris(4-chlorophenyl)sulfonium, several monosubstituted (4-F, 4-Cl, 4-Me, 4-MeO, 4-PhS, and 4-PhCO), and disubstituted (4,4′-Me2 and 4,4′-(MeO)2) triphenylsulfonium salts was examined in solution. It was found that direct irradiation of triphenylsulfonium salts produced new rearrangement products, phenylthiobiphenyls, along with diphenyl sulfide, which had been previously reported. Similarly, the triarylsulfonium salts, with the exception of the [4-(phenylthio)phenyl]diphenylsulfonium salts, gave the new rearrangement products. The mechanism for direct photolysis is proposed to occur from the singlet excited state to give a predominant heterolytic cleavage along with some homolytic cleavage. The heterolytic cleavage gives phenyl cation and diphenyl sulfide, whereas homolytic cleavage gives the singlet phenyl radical and diphenylsulfinyl radical cation pair. These pairs of intermediates then produce the observed photoproducts by an in-cage recombination mechanism and also by reactions with the solvent. The effect of solvent viscosity, solvent polarity, anion, and aryl substituent was examined. The triplet sensitization of the sulfonium salts was also investigated. In contrast to previous reports, the triplet state of the sulfonium salt is labile, leading to a triplet geminate radical pair of phenyl radical and diphenylsulfinyl radical cation. These species ultimately form benzene and diphenyl sulfide as products. Direct photolysis of the [4-(phenylthio)phenyl]diphenylsulfonium salt, gave exclusively diphenyl sulfide, benzene, and acid and decomposes via the triplet excited state.
- Dektar, John L.,Hacker, Nigel P.
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p. 6004 - 6015
(2007/10/02)
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- Chlorination of ortho-substituted phenols
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The ortho-substituted phenols, e.g., 2,6-dichlorophenol, are reacted with gaseous chlorine, in the presence of a catalytically effective amount of a strong or Lewis acid, to produce, e.g., a more pure 2,4,6-trichlorophenol in good yield.
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- Intermolecular activation of C-D bonds in benzene-d6 by trans-neopentyl(trifluoromethanesulfonato)bis(trimethyl-phosphine) platinum (II)
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trans-(Me3P)2Pt(CH2C(CH3) 3)(SO3CF3) (L2PtNpTf, 1) reacts with benzene-d6 at 133°C and gives trans-(Me3P)2Pt(C6D5)(SO 3CF3) (2) and neopentane-d1 as the major products. When this reaction is carried out in concentrated solutions ([1]0 ≥ 0.04 M), small quantities of neopentane-d0 (8-17%) and 1,1-dimethylcyclopropane (1-3%) are also detected; larger quantities of neopentane-d0 are produced (32-45%) when the initial concentration of 1 is low ([1]0 = 0.01-0.03 M). The rate of reaction is decreased by the addition of Bu4N+Tr- and increased by the addition of Bu4N+BF4-. A competitive kinetic isotope effect was estimated by allowing 1 to react with C6D5H and comparing the relative yields of neopentane-d0 and neopentane-d1: kH/kD is large, but its quantitative value is uncertain because of experimental ambiguities. The mechanism for this reaction seems to involve generation of L2PtNp+ as an essential intermediate. This intermediate appears to react with benzene by direct oxidative addition of a C-H bond, but electrophilic attack on the benzene ring cannot be rigorously excluded.
- Brainard, Robert L.,Rodger Nutt,Randall Lee,Whitesides, George M.
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p. 2379 - 2386
(2008/10/08)
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