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Heterogeneous Catalysts (heterogeneous + catalyst)
Kinds of Heterogeneous Catalysts Selected AbstractsSynthesis of Ionic Liquid Functionalized SBA-15 Mesoporous Materials as Heterogeneous Catalyst toward Knoevenagel Condensation under Solvent-Free ConditionsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 15 2006Yong Liu Abstract 1-Methyl-3-propylimidazolium chloride (MPImCl) and 1-propylpyridinium chloride (PPyCl) ionic liquid functionalized SBA-15 mesoporous materials were synthesized and used as heterogeneous catalysts in Knoevenagel reactions with excellent yields and reusability. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Immobilization of Porphyrinatocopper Nanoparticles onto Activated Multi-Walled Carbon Nanotubes and a Study of its Catalytic Activity as an Efficient Heterogeneous Catalyst for a Click Approach to the Three-Component Synthesis of 1,2,3-Triazoles in WaterADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009Hashem Sharghi Abstract An efficient, regioselective, one-pot and two-step synthesis of ,-hydroxy 1,4-disubstituted 1,2,3-triazoles from a wide range of non-activated terminal alkynes and epoxides and sodium azide by way of a three-component click reaction using a catalytic amount of [meso -tetrakis(o -chlorophenyl)porphyrinato]copper(II) (5,mol%) in excellent isolated yields is described. The reactions were performed in water as a green solvent at ambient temperature without any additives. By performing two reaction steps in one pot and purifying only at the final step, this procedure excludes any interim purification of in situ generated organic azide intermediates, which significantly improves the overall yield and reduces the reaction time. To benefit from the recovery and reuse of the catalyst, a new heterogeneous catalyst was prepared by simple and successful impregnation of the catalyst onto activated multi-walled carbon nanotubes (AMWCNT). The heterogeneous catalyst was characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic forced microscopy (AFM), and thermogravimetric (TG) analysis to estimate the amount of nitrogen adsorption, and Raman and FT-IR spectroscopy. Leaching experiments after ten successive cycles showed that the catalyst is most strongly anchored to the AMWCNT support. Mechanistically, porphyrinatocopper catalyzes each step of the reaction in different ways as a bifunctional catalyst including epoxide ring opening by azide delivery to epoxide, forming in situ generated 2-azido alcohols followed by activation of the CC triple bond of the starting terminal alkynes by forming a porphyrinatocopper-acetylide intermediate and thereby promoting the [3+2]-cycloaddition reaction as the key step to form the triazole framework. [source] Nanocrystalline Magnesium Oxide-Stabilized Molybdenum: An Efficient Heterogeneous Catalyst for the Aerobic Oxidation of Alcohols to Carbonyl CompoundsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 16 2008M. Lakshmi Kantam Abstract A nanocrystalline magnesium oxide-stabilized molybdenum(VI) complex catalyzed the oxidation of primary and secondary alcohols to carbonyl compounds in excellent yields using molecular oxygen as stoichiometric oxidant. The nanomaterials with their three-dimensional structure and defined size and shape act as suitable supports for metal complexes. The catalyst can be reused for four runs without any significant loss of activity. [source] Creation of a Monomeric Ruthenium Species on the Surface of Micro-Size Copper Hydrogen Phosphate: An Active Heterogeneous Catalyst for Selective Aerobic Oxidation of AlcoholsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 16 2007Junhua Liu Abstract A new micro-size copper hydrogen phosphate (CHP) synthesized by the emulsion method combined with a monomeric ruthenium species was found to be a very effective catalyst for the selective oxidation of alcohols. Several kinds of alcohols were transformed into the corresponding aldehydes or ketones over the RuCHP catalyst by oxygen under very mild conditions. The results showed that the CHP material was perfect as a catalyst support due to its high ion-exchange ability and adsorption capacity. [source] Nanocrystalline Titanium(IV) Oxide as an Efficient Heterogeneous Catalyst for Tandem Michael and Nucleophilic 1,2-Addition to EnonesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 7-8 2006Lakshmi Kantam Abstract Nanocrystalline titanium(IV) oxide was found to be an efficient heterogeneous catalyst for the conjugate 1,4-addition of indoles with ,,, - unsaturated ketones to afford ,-indolyl ketones in excellent yields. The subsequent catalytic 1,2-addition of Me3SiCN to carbonyl compounds can be performed in one pot with moderate to good yields. Low sensitivity towards traces of moisture and high tolerance of different functional groups make nanocrystalline titanium(IV) oxide suitable for carrying out multistep synthetic sequences. [source] Nanocrystalline ZnO as an Efficient Heterogeneous Catalyst for the Synthesis of 5-Substituted 1H -TetrazolesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2005Kantam, M. Lakshmi Abstract Nanocrystalline ZnO is an effective heterogeneous catalyst for the [2+3]-cycloaddition of sodium azide with nitriles to afford 5-substituted 1H -tetrazoles in good yields. [source] A Practical Heterogeneous Catalyst for the Suzuki, Sonogashira, and Stille Coupling Reactions of Unreactive Aryl Chlorides,ANGEWANDTE CHEMIE, Issue 6 2010Myung-Jong Jin Prof. Praktischer Katalysator: Ein Palladiumkatalysator, der auf einem magnetischen Nanopartikel fixiert ist, wurde für hocheffiziente heterogene Suzuki-, Sonogashira- und Stille-Kupplungen einer Vielzahl von Arylchloriden entwickelt. Darüber hinaus ließ sich der Katalysator durch einfache magnetische Trennung ohne jeglichen Aktivitätsverlust zurückgewinnen. TBAB=Tetrabutylammoniumbromid. [source] ChemInform Abstract: Indium Modified Mesoporous Zeolite AlMCM-41 as a Heterogeneous Catalyst for the Knoevenagel Condensation Reaction.CHEMINFORM, Issue 40 2010Santosh S. Katkar Abstract The indium-modified mesoporous zeolite AlMCM-41 is used as heterogeneous catalyst for the Knoevenagel reaction of aromatic aldehydes (I) and activated methylene compounds (II). [source] ChemInform Abstract: Chemoselective Protection of Aldehydes in the Presence of Ketones Using RuPVP Complex as a Heterogeneous Catalyst.CHEMINFORM, Issue 26 2010Siddheshwar W. Kshirsagar 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: Mesoporous ZnS Nanospheres: A High Activity Heterogeneous Catalyst for Synthesis of 5-Substituted 1H-Tetrazoles from Nitriles and Sodium Azide.CHEMINFORM, Issue 19 2010Leiming Lang 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: Pd(OAc)2 Immobilized on Fe3O4 as Magnetically Separable Heterogeneous Catalyst for Suzuki Reaction in Water.CHEMINFORM, Issue 18 2010Ji-Young Jung 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: A Tin,Tungsten Mixed Oxide as an Efficient Heterogeneous Catalyst for C,C Bond-Forming Reactions.CHEMINFORM, Issue 35 2009Yoshiyuki Ogasawara 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: [,-PW12O40]3- Immobilized on Ionic Liquid Modified Polymer as a Heterogeneous Catalyst for Alcohol Oxidation with Hydrogen Peroxide.CHEMINFORM, Issue 44 2008Xianjun Lang 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: Silica Supported Perchloric Acid (HClO4,SiO2): An Efficient and Recyclable Heterogeneous Catalyst for the One-Pot Synthesis of Amidoalkyl Naphthols.CHEMINFORM, Issue 35 2008Hamid Reza Shaterian 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: Immobilization of Ruthenium in Organic,Inorganic Hybrid Copolymers: A Reusable Heterogeneous Catalyst for Oxidation of Alcohols with Molecular Oxygen.CHEMINFORM, Issue 23 2008Tsutomu Matsumoto 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: Covalently Anchored Sulfonic Acid on Silica Gel as an Efficient and Reusable Heterogeneous Catalyst for the One-Pot Synthesis of Hantzsch 1,4-Dihydropyridines under Solvent-Free Conditions.CHEMINFORM, Issue 7 2008Raman Gupta 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] Silica-Supported ZnCl2 , A Highly Active and Reusable Heterogeneous Catalyst for the One-Pot Synthesis of Dihydropyrimidinones,Thiones.CHEMINFORM, Issue 43 2007Raman Gupta 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, please click on HTML or PDF. [source] An Efficient Reusable Silver-Exchanged Tungstophosphoric Acid Heterogeneous Catalyst for Solvent-Free Intermolecular Hydroamination of Alkynes.CHEMINFORM, Issue 19 2007N. Lingaiah 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, please click on HTML or PDF. [source] Heterogeneous Catalyst: Amberlyst-15 Catalyzes the Synthesis of 14-Substituted-14H-dibenzo[a,j]xanthenes under Solvent-Free Conditions.CHEMINFORM, Issue 14 2007Shengkai Ko 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, please click on HTML or PDF. [source] Microwave-Promoted Facile and Rapid Solvent-Free Synthesis Procedure for the Efficient Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones and -thiones Using ZrO2/SO42- as a Reusable Heterogeneous Catalyst.CHEMINFORM, Issue 50 2006Mannathusamy Gopalakrishnan 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, please click on HTML or PDF. [source] A Rhodium-Grafted Hydrotalcite as a Highly Efficient Heterogeneous Catalyst for 1,4-Addition of Organoboron Reagents to ,,,-Unsaturated Carbonyl Compounds.CHEMINFORM, Issue 44 2006Noriaki Fujita 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, please click on HTML or PDF. [source] Synthesis of Pyrano and Furanoquinolines Using Silica Chloride or Amberlyst-15 as a Heterogeneous Catalyst.CHEMINFORM, Issue 16 2006Biswanath Das 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, please click on HTML or PDF. [source] WO3 Nanoparticles on MCM-48 as a Highly Selective and Versatile Heterogeneous Catalyst for the Oxidation of Olefins, Sulfides, and Cyclic Ketones.CHEMINFORM, Issue 10 2006Dong Hyun Koo 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, please click on HTML or PDF. [source] ChemInform Abstract: Cu-Exchanged Y-Zeolite: A Heterogeneous Catalyst for the Synthesis of ,-Aminoketones.CHEMINFORM, Issue 40 2001Prodeep Phukan 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: A One-Step, Enantioselective Reduction of Ethyl Nicotinate to Ethyl Nipecotinate Using a Constrained, Chiral, Heterogeneous Catalyst.CHEMINFORM, Issue 2 2001Stuart A. Raynor 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] MCM-41 Bound Ruthenium Complex as Heterogeneous Catalyst for Hydrogenation I: Effect of Support, Ligand and Solvent on the Catalyst PerformanceCHINESE JOURNAL OF CHEMISTRY, Issue 7 2006Ying-Min Yu Abstract The functionalized MCM-41 mesoporous bound ruthenium complex was synthesized and characterized using elemental analysis, atomic absorption spectrophotometer, BET, XRD and FTIR. Hydrogenation of carbon dioxide to formic acid was investigated over these catalysts under supercritical CO2 condition. The effect of reactant gas partial pressure, supports, solvents and ligands on the synthesis of formic acid was studied. These factors could influence the catalyst activity, stability and reuse performance greatly and no byproduct was detected. These promising catalysts also offered the industrial advantages such as easy separation. [source] Grafting of Molecularly Ordered Mesoporous Phenylene-Silica with Molybdenum Carbonyl Complexes: Efficient Heterogeneous Catalysts for the Epoxidation of OlefinsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2010Abstract Arenetricarbonyl complexes, or the general formula C6H4Mo(CO)3, were incorporated into crystal-like mesoporous phenylene-silica by liquid-phase deposition of molybdenum hexacarbonyl [Mo(CO)6]. By adjusting the reaction conditions, different molybdenum loadings of 1.5 and 5.9,wt% were obtained, which correspond to 3% and 14% of the phenylene contents. The texture properties of the materials as well as the nature of the surface-fixed complexes were characterized by powder X-ray diffraction, transmission electron microscopy (TEM), N2 adsorption, FT-IR, UV-vis and MAS (13C, 29Si) NMR spectroscopy. The derivatized organosilicas were examined as catalyst precursors for the liquid-phase epoxidation of cis -cyclooctene, 1-octene, trans -2-octene and (R)-(+)-limonene at 55,°C, using tert -butyl hydroperoxide as the oxidant. For each olefin the corresponding epoxide was the only product detected. In the case of cyclooctene, the intrinsic reaction rates per surface molybdenum atom were similar for both Mo loadings (TOF,1150 mol,molMo,1,h,1), suggesting that the resultant materials act as single site epoxidation catalysts. Leaching tests and metal analyses of reaction solutions showed that the catalytic activity stemmed from the immobilized species and not from the leaching of active species into solution. The oxidation of limonene gave limonene oxide as the only product in 95% yield at 3,h, which reveals an outstanding regioselectivity to the epoxidation of the endocyclic double bond. [source] Selective Hydrogenation of 5-Ethoxymethylfurfural over Alumina-Supported Heterogeneous CatalystsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 18 2009Erik-Jan Ras Abstract We report here the synthesis and testing of a set of 48 alumina-supported catalysts for hydrogenation of 5-ethoxymethylfurfural. This catalytic reaction is very important in the context of converting biomass to biofuels. The catalysts are composed of one main metal (gold, copper, iridium, nickel, palladium, platinum, rhodium, ruthenium) and one promoter metal (bismuth, chromium, iron, sodium, tin, tungsten). Using a 16-parallel trickle-flow reactor, we tested all 48 catalyst combinations under a variety of conditions. The results show that both substrate conversion and product selectivity are sensitive towards temperature changes and solvent effects. The best results of >99% yield to the desired product, 5-ethoxymethylfurfuryl alcohol, are obtained using an iridium/chromium (Ir/Cr) catalyst. The mechanistic implications of different possible reaction pathways in this complex hydrogenation system are discussed. [source] Metal-Organic Frameworks (MOFs) as Heterogeneous Catalysts for the Chemoselective Reduction of Carbon-Carbon Multiple Bonds with HydrazineADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009Amarajothi Dhakshinamoorthy Abstract The as-synthesized metal-organic frameworks (MOFs), particularly that based on aluminium coordinated with benzenedicarboxylic acid, constitute selective catalysts for the reduction of carbon-carbon multiple bonds in alkenes, alkynes and ,,,-unsaturated esters with hydrazine hydrate in acetonitrile under mild conditions. The present protocol enjoys advantages such as convenient reaction conditions and benign, reusable and cost effective catalyst. [source] Silica Supported Sodium Hydrogen Sulfate and Amberlyst-15: Two Efficient Heterogeneous Catalysts for Facile Synthesis of Bis- and Tris(1H -indol-3-yl)methanes from Indoles and Carbonyl Compounds[1]ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 5 2003Chimmani Ramesh Abstract Bis- and tris(1H -indol-3-yl)methanes are synthesized in high yields by an electrophilic substitution reaction of indoles with carbonyl compounds under mild reaction conditions using two efficient heterogeneous catalysts, silica supported sodium hydrogen sulfate (NaHSO4,SiO2) and amberlyst-15. The second catalyst can be reused. [source] | ||||||||||||||||||||||||||||||||||