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Carboxylic Acids (carboxylic + acid)
Kinds of Carboxylic Acids Terms modified by Carboxylic Acids Selected AbstractsThe Structure of the First Supramolecular ,-Cyclodextrin Complex with an Aliphatic Monofunctional Carboxylic AcidEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 26 2007Saddys Rodríquez-Llamazares Abstract The crystal structure of the supramolecular complex between ,-cyclodextrin and decanoic acid was determined: The aliphatic chain of the carboxylic acid is threaded through a head-to-head dimer of two cyclodextrin residues, resulting in a 1:2 stoichiometry. Head-to-head orientation is also observed between neighboring complexes. The overall degree of hydration with 25 water molecules per supramolecular complex is remarkably high. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] ChemInform Abstract: A Convenient Method to Reduce Hydroxyl-Substituted Aromatic Carboxylic Acid with NaBH4/Me2SO4/B(OMe)3.CHEMINFORM, Issue 35 2008Yuhan Zhou Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Esterification of Alkene with Cerium(IV) Sulfate in Carboxylic Acid.CHEMINFORM, Issue 2 2004C. Akira Horiuchi Abstract For Abstract see ChemInform Abstract in Full Text. [source] A Novel and Convenient Chemoselective Deprotection Method for Both Silyl and Acetyl Groups on Acidic Hydroxyl Groups such as Phenol and Carboxylic Acid by Using a Nitrogen Organic Base, 1,1,3,3-Tetramethylguanidine.CHEMINFORM, Issue 21 2003Kin-ichi Oyama No abstract is available for this article. [source] Selective Phenolic Acylation of 10-Hydroxycamptothecin Using Poly (Ethylene Glycol) Carboxylic Acid.CHEMINFORM, Issue 18 2003Richard B. Greenwald No abstract is available for this article. [source] Variable-Temperature Powder X-ray Diffraction of Aromatic Carboxylic Acid and Carboxamide CocrystalsCHEMISTRY - AN ASIAN JOURNAL, Issue 4 2007L. Sreenivas Reddy Abstract The effect of temperature on the cocrystallization of benzoic acid (BA), pentafluorobenzoic acid (FBA), benzamide (BAm), and pentafluorobenzamide (FBAm) is examined in the solid state. BA and FBA formed a 1:1 complex 1 at ambient temperature by grinding with a mortar and pestle. Grinding FBA and BAm together resulted in partial conversion into the 1:1 adduct 2 at 28,°C and complete transformation into the product cocrystal at 78,°C. Further heating (80,100,°C) and then cooling to room temperature gave a different powder pattern from that of 2. BAm and FBAm hardly reacted at ambient temperature, but they afforded the 1:1 cocrystal 3 by melt cocrystallization at 110,115,°C. Both BA+FBAm (4) and BA+BAm (5) reacted to give new crystalline phases upon heating, but the structures of these products could not be determined owing to a lack of diffraction-quality single crystals. The stronger COOH and CONH2 hydrogen-bonding groups of FBA and FBAm yielded the equimolar cocrystal 6 at room temperature, and heating of these solids to 90,100,°C gave a new crystalline phase. The X-ray crystal structures of 1, 2, 3, and 6 are sustained by the acid,acid/amide,amide homosynthons or acid,amide heterosynthon, with additional stabilization from phenyl,perfluorophenyl stacking in 1 and 3. The temperature required for complete transformation into the cocrystal was monitored by in,situ variable-temperature powder X-ray diffraction (VT-PXRD), and formation of the cocrystal was confirmed by matching the experimental peak profile with the simulated diffraction pattern. The reactivity of H-bonding groups and the temperature for cocrystallization are in good agreement with the donor and acceptor strengths of the COOH and CONH2 groups. It was necessary to determine the exact temperature range for quantitative cocrystallization in each case because excessive heating caused undesirable phase transitions. [source] Drastic Solid-State Fluorescence Enhancement Behaviour of Phenanthro[9,10- d]imidazole-Type Fluorescent Hosts upon Inclusion of Carboxylic AcidsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 34 2009Yousuke Ooyama Abstract The crystals of phenanthro[9,10- d]imidazole-type fluorescent host 1 exhibit drastic fluorescence enhancement behaviour with a redshift in the emission maximum upon enclathration of various carboxylic acids such as formic acid, acetic acid and propionic acid. The optical changes are greatly dependent on the identity of the enclathrated carboxylic acids. The fluorescent clathrate compounds are formed not only by cocrystallization from carboxylic acid solutions but also by solid (fluorescent host),gas (carboxylic acid vapour) contact. Furthermore, when the acetic acid inclusion crystals are exposed to propionic acid vapour, acetic acid is gradually replaced by propionic acid. The guest exchange of the inclusion crystals was accompanied with colour and fluorescent intensity changes. The X-ray structural analyses of the guest-free and carboxylic acid inclusion compounds demonstrated that the destructions of the ,,, interactions, and the intermolecular hydrogen bonds binding fluorophores were induced by the enclathrated carboxylic acid molecules. Moreover, the imidazole ring of the host is protonated by the enclathrated carboxylic acid proton. On the basis of the spectroscopic data and the crystal structures, the effects of the enclathrated carboxylic acid on the solid-state photophysical properties of the clathrate compounds are discussed.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Reaction of Carboxylic Acids with Isocyanides: A Mechanistic DFT StudyEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 28 2008Tommaso Marcelli Abstract We present a computational investigation of the reaction between isocyanides and carboxylic acids. Our results indicate that this reaction begins with a stereoselective concerted ,-addition of the acid to the isocyanide, leading exclusively to a Z -acyl imidate. Isomerization to the E isomer and successive rate-limiting 1,3 O,N acyl migration yields an N -formyl imide. The calculated barriers are in good agreement with the experimental reaction conditions. Our results might provide an explanation for the peculiar reactivity observed when this reaction is carried out in a self-assembled capsule. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Novel Catalytic Tandem Isomerisation/Cyclisation Reaction of ,-Methallyloxy Carboxylic AcidsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 16 2006Xavier Chaminade Abstract A new tandem isomerisation/cyclisation of ,-methallyloxy carboxylic acids leading to substituted 1,3-dioxolan-4-ones in 60,70,% yields was catalysed by Cu(OTf)2 or Al(OTf)3. Extension to the synthesis of oxathiolanones and oxathianones is also described. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Metal-Free and Copper-Promoted Single-Pot Hydrocarboxylation of Cycloalkanes to Carboxylic Acids in Aqueous MediumADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 17 2009Marina Abstract A simple and effective method for the transformation, under mild conditions and in aqueous medium, of various cycloalkanes (cyclopentane, cyclohexane, methylcyclohexane, cis - and trans -1,2-dimethylcyclohexane, cycloheptane, cyclooctane and adamantane) into the corresponding cycloalkanecarboxylic acids bearing one more carbon atom, is achieved. This method is characterized by a single-pot, low-temperature hydrocarboxylation reaction of the cycloalkane with carbon monoxide, water and potassium peroxodisulfate in water/acetonitrile medium, proceeding either in the absence or in the presence of a metal promoter. The influence of various reaction parameters, such as type and amount of metal promoter, solvent composition, temperature, time, carbon monoxide pressure, oxidant and cycloalkane, is investigated, leading to an optimization of the cyclohexane and cyclopentane carboxylations. The highest efficiency is observed in the systems promoted by a tetracopper(II) triethanolaminate-derived complex, which also shows different bond and stereoselectivity parameters (compared to the metal-free systems) in the carboxylations of methylcyclohexane and stereoisomeric 1,2-dimethylcyclohexanes. A free radical mechanism is proposed for the carboxylation of cyclohexane as a model substrate, involving the formation of an acyl radical, its oxidation and consequent hydroxylation by water. Relevant features of the present hydrocarboxylation method, besides the operation in aqueous medium, include the exceptional metal-free and acid-solvent-free reaction conditions, a rare hydroxylating role of water, substrate versatility, low temperatures (ca. 50,°C) and a rather high efficiency (up to 72% carboxylic acid yields based on cycloalkane). [source] The Aerobic Oxidative Cleavage of Lignin to Produce Hydroxyaromatic Benzaldehydes and Carboxylic Acids via Metal/Bromide Catalysts in Acetic Acid/Water MixturesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 3 2009Walt Partenheimer Abstract Roughly 30% of all woody plants is composed of lignin. Five different lignin samples, from wood and bagasse, were oxidized in air with a cobalt/manganese/zirconium/bromide (Co/Mn/Zr/Br) catalyst in acetic acid as a function of time, temperature, pressure, and lignin and catalyst concentrations. 18 products were identified via gas chromatography-mass spectrometry (GC/MS). The most valuable products from lignin were 4-hydroxybenzaldehyde, 4-hydroxybenzoic acid, 4-hydroxy-3-methoxybenzaldehyde (vanillin), 4-hydroxy-3-methoxybenzoic acid (vanillic acid), 4-hydroxy-3,5-dimethoxybenzaldehyde (syringaldehyde) and 4-hydroxy-3,5-dimethoxybenzoic acid (syringic acid). 10.9,wt% of the lignin was converted to the aromatic products. By the use of model compounds we demonstrate that 1) the presence of the phenolic functionality on an aromatic ring does inhibit the rate of reaction but that the alkyl group on the ring still does oxidize to the carboxylic acid, 2) that the masking of phenol by acetylation occurs at a reasonable rate in acetic acid, 3) that the alkyl group of the masked phenol does very readily oxidize, 4) that an acetic anhydride/acetic acid mixture is a good oxidation solvent and 5) that a two-step acetylation/oxidation to the carboxylic acid is feasible. [source] Selective Oxidation of Alcohols to Carbonyl Compounds and Carboxylic Acids with Platinum Group Metal CatalystsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 4 2003Ross Anderson Abstract The use of platinum group metal (PGM) catalysts for the selective oxidation of various primary and secondary alcohols under mild conditions is described. High throughput screening (HTS) techniques have been used to identify trends in catalyst activity and product selectivity. Using air as oxidant and water as solvent 5% Pt, 1% Bi/C has been identified as an efficient catalyst for the transformation of 2-octanol to 2-octanone and 1-octanol to octanoic acid. To improve aldehyde selectivity the promotion of Pt/Al2O3 and Ru/C catalysts has been investigated. The use of H2O2 as oxidant has been demonstrated as a suitable alternative to air. [source] Silicon Analogues of Carboxylic Acids: Synthesis of Isolable Silanoic Acids by Donor,Acceptor Stabilization,ANGEWANDTE CHEMIE, Issue 37 2010Yun Xiong Dr. Was tun bei Instabilität? Lagerfähige Silacarbonsäurekomplexe wurden durch Addition von H2S bzw. H2OB(C6F5)3 an den Silanonvorläuferkomplex 1 erhalten. Metallierung der OH-Gruppe im Säure-Base-Addukt 2 lieferte das neuartige Silathiocarboxylat 3. Zudem gelang die Synthese der ersten Donor-Akzeptor- stabilisierten Silanonsäure. L=4-Dimethylaminopyridin, R=2,6-Diisopropylphenyl. [source] Regioselective Oxidative Cleavage of Benzylidene Acetals: Synthesis of ,- and ,-Benzoyloxy Carboxylic Acids,ANGEWANDTE CHEMIE, Issue 4 2010Ponminor, Senthil Kumar Ruthenium hat doppelt Spaß: Das Synthesepotential der hoch regio- und stereoselektiven Titelreaktion, die zwei durch RuCl3 in Kombination mit NaIO4 ermöglichte oxidative Spaltungsschritte nutzt (siehe Beispiel; Bz=Benzoyl), wurde mit der Synthese der biologisch aktiven cis -(2R,3S) - 3-Hydroxypipecolsäure aus D -Glucose nachgewiesen. [source] Comparative Study of Copper- and Silver-Catalyzed Protodecarboxylations of Carboxylic AcidsCHEMCATCHEM, Issue 4 2010Lukas Abstract The protodecarboxylation of aromatic carboxylic acids by various copper and silver catalysts is investigated with the help of density functional calculations and experimental studies. The computational results reveal that the catalytic activity of copper(I),1,10-phenanthroline catalysts increases with the introduction of electron-rich substituents at the phenanthroline ligand. They also predicted that for some substrates, silver complexes should possess a substantially higher decarboxylating activity than copper, which is confirmed by experimental studies, leading to the discovery of a silver(I) catalyst that effectively promotes the protodecarboxylation of various carboxylic acids at temperatures in the range of 80,120,°C,more than 50,°C below those of the best known copper(I) catalyst. The scope of the new system complements that of the copper(I)-based method as it includes benzoates for example, with halogen or ether groups in the ortho positions. [source] ChemInform Abstract: T3P® (Propylphosphonic Anhydride) Mediated Conversion of Carboxylic Acids into Acid Azides and One-Pot Synthesis of Ureidopeptides.CHEMINFORM, Issue 35 2010Basavaprabhu Basavaprabhu Abstract The method is high-yielding and ecofriendly. [source] ChemInform Abstract: A Convenient One-Pot Method for the Synthesis of N-Methoxy-N-methyl Amides from Carboxylic Acids.CHEMINFORM, Issue 20 2010Joong-Gon Kim Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Synthesis of Thioesters by Simultaneous Activation of Carboxylic Acids and Alcohols Using PPh3/NBS with Benzyltriethylammonium Tetrathiomolybdate as the Sulfur Transfer Reagent.CHEMINFORM, Issue 12 2010Purushothaman Gopinath Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Silver Nitrate Catalyzed Oxidation of Aldehydes to Carboxylic Acids by H2O2.CHEMINFORM, Issue 9 2010Debashis Chakraborty Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Polymer-Assisted Solution-Phase Synthesis under Combined Ultrasound and Microwave Irradiation: Preparation of ,,,-Unsaturated Esters and Carboxylic Acids, Key Intermediates of Novel Sigma Ligands.CHEMINFORM, Issue 4 2010D. Rossi Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: TEMPO-Mediated Oxidation of Primary Alcohols to Carboxylic Acids by Exploitation of Ethers in an Aqueous,Organic Biphase System.CHEMINFORM, Issue 52 2009Zhen-Wu Mei Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Synthesis of Condensed Heteroaromatic Compounds by Palladium-Catalyzed Oxidative Coupling of Heteroarene Carboxylic Acids with Alkynes.CHEMINFORM, Issue 45 2009Mana Yamashita Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Four-Component Reaction of Isocyanides, Acetylenic Esters, and Carboxylic Acids for the Synthesis of Functionalized 2,5-Diaminofurans.CHEMINFORM, Issue 44 2009Mohammad Anary-Abbasinejad Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: One-Pot Curtius Rearrangement Processes from Carboxylic Acids.CHEMINFORM, Issue 43 2009Olivier Leogane Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Strecker-Type Reaction Catalyzed by Carboxylic Acids in Aqueous Media.CHEMINFORM, Issue 43 2009Zhengfeng Xie Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: One-Pot Synthesis of Phenacyl Esters from Acetophenone, [Bmim]Br3, and Potassium Salts of Carboxylic Acids under Solvent-Free Conditions.CHEMINFORM, Issue 32 2009Zhang-Gao Le Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Catalytic Staudinger,Vilarrasa Reaction for the Direct Ligation of Carboxylic Acids and Azides.CHEMINFORM, Issue 30 2009Jordi Bures Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Asymmetric Synthesis of Both Antipodes of ,-Hydroxy Nitriles and ,-Hydroxy Carboxylic Acids via Enzymatic Reduction or Sequential Reduction/Hydrolysis.CHEMINFORM, Issue 26 2009Haribabu Ankati Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Convenient One-Pot Synthesis of 2-Oxazolines from Carboxylic Acids.CHEMINFORM, Issue 21 2009Kazuhito Hioki Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: The Thermal Amidation of Carboxylic Acids Revisited.CHEMINFORM, Issue 19 2009Lukas J. Goossen Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. 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