- Towards the Discrimination of Carboxylates by Hydrogen-Bond Donor Anion Receptors
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The binding constants (log Kass) of small synthetic receptor molecules based on indolocarbazole, carbazole, indole, urea and some others, as well as their combinations were measured for small carboxylate anions of different basicity, hydrophili
- Kadam, Sandip A.,Martin, Kerli,Haav, Kristjan,Toom, Lauri,Mayeux, Charly,Pung, Astrid,Gale, Philip A.,Hiscock, Jennifer R.,Brooks, Simon J.,Kirby, Isabelle L.,Busschaert, Nathalie,Leito, Ivo
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- Ionic Liquid Stabilized Niobium Oxoclusters Catalyzing Oxidation of Sulfides with Exceptional Activity
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We present here a new class of niobium oxoclusters that are stabilized effectively by carboxylate ionic liquids. These functionalized ILs are designated as [TBA][LA], [TBA][PA], and [TBA][HPA] in this work, in which TBA represents tetrabutylammonium and LA, PA, and HPA refer to lactate, propionate, 3-hydroxypropionate anions, respectively. The as-synthesized Nb oxoclusters have been characterized by use of elemental analysis, NMR, IR, XRD, TGA, HRTEM. It was found that [TBA][LA]-stabilized Nb oxoclusters (Nb?OC@[TBA][LA]) are uniformly dispersed with an average particle size of 2–3 nm and afforded exceptionally high catalytic activity for the selective oxidation of various thioethers. The turnover number with Nb?OC@[TBA][LA] catalyst was over 56 000 at catalyst loading as low as 0.0033 mol % (1 ppm). Meantime, the catalyst also showed the high activity for the epoxidation of olefins and allylic alcohols by using only 0.065 mol % of catalyst (50 ppm). The characterization of 93Nb NMR spectra revealed that the Nb oxoclusters underwent structural transformation in the presence of H2O2 but regenerated to their initial state at the end of the reaction. In particular, the highly dispersed Nb oxoclusters can absorb a large amount of polar organic solvents and thus were swollen greatly, which exhibited “pseudo” liquid phase behavior, and enabled the substrate molecules to be highly accessible to the catalytic center of Nb oxocluster units.
- Zhou, Qingqing,Ye, Man,Ma, Wenbao,Li, Difan,Ding, Bingjie,Chen, Manyu,Yao, Yefeng,Gong, Xueqing,Hou, Zhenshan
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p. 4206 - 4217
(2019/03/26)
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- BIOCATALYST SOLVENT USING IONIC LIQUID, AND BIOCATALYST SOLUTION CONTAINING THE SOLVENT AND BIOCATALYST
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PROBLEM TO BE SOLVED: To provide: a biocatalyst solvent that can be stored for a long period of time and that can dissolve a high concentration of a biocatalyst from low temperatures to high temperatures while retaining the activity of the biocatalyst; and a biocatalyst solution using the biocatalyst solvent. SOLUTION: The biocatalyst solvent is composed of an ionic liquid containing anions and quaternary ammonium cations represented by the following formula (1), where each Ra independently represents: a hydroxyalkyl group which has at least one hydroxyl group, in which the alkyl moiety is in a C1-10 straight-chained or branched state, and in which the alkyl moiety may contain an oxygen atom; a carboxyalkyl group which has at least one carboxy group, in which the alkyl moiety is in a C1-10 straight-chained or branched state, and in which the alkyl moiety may contain an oxygen atom; or a hydroxy-carboxyalkyl group which has at least one each of a hydroxyl group and a carboxy group, in which the alkyl moiety is in a C1-10 straight-chained or branched state, and in which the alkyl moiety may contain an oxygen atom and where each Rb independently represents a hydrogen atom or a C1-5 straight-chained or branched alkyl group. n represents an integer of 1-4. SELECTED DRAWING: None COPYRIGHT: (C)2016,JPOandINPIT
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Paragraph 0157-0159
(2016/10/10)
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- Synthesis of tertiary and quaternary amine derivatives from wood resin as chiral NMR solvating agents
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Chiral tertiary and quaternary amine solvating agents for NMR spectroscopy were synthesized from the wood resin derivative (+)-dehydroabietylamine (2). The resolution of enantiomers of model compounds [Mosher's acid (3) and its n-Bu4N salt (4)] (guests) by (+)-dehydroabietyl-N,N-dimethylmethanamine (5) and its ten different ammonium salts (hosts) was studied. The best results with 3 were obtained using 5 while with 4 the best enantiomeric resolution was obtained using (+)-dehydroabietyl-N,N-dimethylmethanaminium bis(trifluoromethane-sulfonimide) (6). The compounds 5 and 6 showed a 1:1 complexation behaviour between the host and guest. The capability of 5 and 6 to recognize the enantiomers of various α-substituted carboxylic acids and their n-Bu4N salts in enantiomeric excess (ee) determinations was demonstrated. A modification of the RES-TOCSY NMR pulse sequence is described, allowing the enhancement of enantiomeric discrimination when the resolution of multiplets is insufficient.
- Laaksonen, Tiina,Heikkinen, Sami,W?h?l?, Kristiina
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p. 20873 - 20886
(2015/12/23)
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- Biomass derived ionic liquids: Synthesis from natural organic acids, characterization, toxicity, biodegradation and use as solvents for catalytic hydrogenation processes
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Ionic liquids with natural organic derived anions (l-lactate, l-tartrate, malonate, succinate, l-malate, pyruvate, d-glucuronate, d-galacturonate) were easily prepared from tetrabutylammonium hydroxide and an excess of the corresponding acid with good yields. Their characterization was realized through classical NMR, IR, and elemental analysis techniques; their viscosity and TGA (thermogravimetric analysis) parameters were also determined. These ionic liquids showed good performance and recyclability in the selective catalytic hydrogenation of 1,5-cyclooctadiene (1,5-COD) into cyclooctene (COD) at room temperature under atmospheric H2 pressure. Antimicrobial toxicity assays toward a large panel of bacteria and fungi strains were also completed and biodegradation studies (Closed Bottle test, 28 days) were also performed.
- Ferlin, Nadège,Courty, Matthieu,Gatard, Sylvain,Spulak, Marcel,Quilty, Brid,Beadham, Ian,Ghavre, Mukund,Hai?, Annette,Kümmerer, Klaus,Gathergood, Nicholas,Bouquillon, Sandrine
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p. 6150 - 6161
(2013/07/25)
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- Chiral thiouronium salts: Synthesis, characterisation and application in NMR enantio-discrimination of chiral oxoanions
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Chiral thioureas and functionalised chiral thiouronium salts were synthesised starting from the relatively cheap and easily available chiral amines: (S)-methylbenzylamine and rosin-derived (+)-dehydroabietylamine. The introduction of a delocalised positiv
- Foreiter, Magdalena B.,Gunaratne, H. Q. Nimal,Nockemann, Peter,Seddon, Kenneth R.,Stevenson, Paul J.,Wassell, David F.
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p. 515 - 533
(2013/03/13)
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- Chiral ionic liquids improved the asymmetric cycloaddition of CO 2 to epoxides
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The new catalyst system of chiral SalenCo(OAc)/chiral ionic liquid was developed to catalyze the asymmetric cycloaddition reaction of CO2 and epoxides yielding the chiral cyclic carbonates. The synergistic effect between them is discussed.
- Zhang, Suling,Huang, Yongzhong,Jing, Huanwang,Yao, Weixuan,Yan, Peng
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supporting information; experimental part
p. 935 - 938
(2010/04/23)
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- Enantioselective lactate binding by chiral tripodal anion hosts derived from amino acids
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Chiral, tripodal anion hosts derived from either S-phenylalanine or S-leucine bind d-lactate enantioselectively. The nature of the host-guest interaction has been probed by solution NMR methods and by DFT calculations. The calculations suggest that the d-
- Barnard, Anna,Dickson, Sara Jane,Paterson, Martin J.,Todd, Adam M.,Steed, Jonathan W.
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experimental part
p. 1554 - 1561
(2009/06/27)
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