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Catalytic
Terms modified by Catalytic Selected AbstractsIntramolecular Heck Reactions for the Synthesis of the Novel Antibiotic Mensacarcin: Investigation of Catalytic, Electronic and Conjugative Effects in the Preparation of the Hexahydroanthracene CoreEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 9 2005Lutz F. Tietze Abstract The intramolecular Heck reaction of the three complex diphenyl substrates rac - 2, 5 and rac - 6, containing substituents with different electronic and conjugative properties, were examined. The Pd compounds [Pd2(dba)3]/[(tBu)3PH]BF4, [Pd2(OAc)2{P(o -Tol)3}2] (4), [PdCl2(PPh3)2] and Pd(OAc)2 were used as catalysts. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Catalytic, Asymmetric Vinylogous Mukaiyama Aldol Reactions of Pyrrole- and Furan-Based Dienoxy Silanes: How the Diene Heteroatom Impacts StereocontrolADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2010Claudio Curti Abstract Denmark's chiral bisphosphoramide/silicon tetrachloride system performs as an excellent Lewis base-Lewis acid catalyst for the vinylogous Mukaiyama aldol reaction of pyrrole- and furan-based dienoxy silanes with aromatic and heteroaromatic aldehydes. This asymmetric methodology provides a powerful synthetic entry to a variety of ,-hydroxylated ,-butenolide-type frameworks with high efficiency and valuable margins of regio-, diastereo-, and enantioselectivity. Notably, the nature of the heteroatom within the vinylogous dienoxy silane donor heavily impacts the diastereocontrol, with syn -configured aldol adducts emerging from pyrroles bearing electron-withdrawing N -protecting groups (Boc, Ts, and Cbz) and anti -configured adducts prevailing when furan- or N -alkyl/alkenylpyrrole donors are involved. [source] Catalytic 1,2-Dicyanation of Alkynes by Palladium(II) under Aerobic ConditionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2009Shigeru Arai Abstract A stereoselective 1,2-dicyanation of various alkynes in the presence of trimethylsilyl cyanide (TMSCN) by palladium(II) catalysis under aerobic conditions is investigated. This reaction includes two cyanation pathways, syn - and anti -cyanopalladation to alkynes that are activated by Pd(II). High syn -selectivity was observed in the reaction using terminal alkynes that have bulky substituents at a propargyl position and aliphatic internal alkynes. Furthermore, a dramatic acceleration was observed with substrates having an N -arenesulfonyl functionality at a propargyl position, this indicates that both sulfoxide and carbon-carbon triple bond act as Lewis bases to Pd(II). [source] A Catalytic and Enantioselective Synthesis of trans- 2-Amino-1- aryltetralinsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2009Saumen Hajra Abstract The bis-oxazoline-copper complex-catalyzed aziridination of alkenes followed by an intramolecular Friedel,Crafts alkylation of the tethered and in situ generated aziridine provides a one-pot, general and efficient method for the synthesis of trans -2-amino - 1-aryltetralins from a mixture of 2- arylethylstyrenes (E/Z,85:15) with excellent dia- stereo- (dr>99:1) and enantioselectivities (up to 92% ee). [source] Catalytic hydrothermal treatment of pine wood biomass: effect of RbOH and CsOH on product distributionJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 10 2005Selhan Karagöz Abstract Low-temperature hydrothermal treatment of pine wood biomass was performed in the presence of RbOH and CsOH catalysts (280 °C for 15 min). The effect of the catalysts on the distribution of products and the volatility distribution of oxygenated hydrocarbons was studied in detail. Oxygenated hydrocarbons were extracted from the liquid and solid portions and analysed individually by gas chromatography/mass spectrometry. Catalytic (RbOH and CsOH) hydrothermal treatment of wood biomass produced mainly phenolic compounds and benzenediol derivatives. The use of RbOH and CsOH catalysts hindered the formation of char and favoured the formation of oil products, as observed previously for various other base catalysts. The volatility distribution of hydrocarbons (ether extract) was characterised by carbon-normal paraffin (C-NP) gram and it was found that the oxygenated hydrocarbons from all runs, including thermal, were distributed in the boiling point region of n-C6 to n-C17. Copyright © 2005 Society of Chemical Industry [source] Catalytic and inhibitory effects of ,-cyclodextrin on the hydrolysis of benzoic anhydrideJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 5 2004Tiago A. S. Brandão Abstract The hydrolysis of benzoic anhydride (Bz2O) in the presence of ,-cyclodextrin (,-CD) was studied in aqueous solution as a function of pH, temperature and ionic strength, at 25°C. The experimental rate constant versus pH profiles show that, in the region of spontaneous water reaction (pH 3.0,6.5), ,-CD inhibits the reaction and the isotope effect indicates that the rate determining step of the reaction corresponds to the water-catalyzed nucleophilic attack of water on the carbonyl group of Bz2O. Conversely, whereas inhibition is observed at pH 6.0, catalysis of the hydroxide ion reaction is observed at pH 8.0 and it is found that the activation entropy is responsible for the catalytic phenomena in the basic hydrolysis of benzoic anhydride. Copyright © 2004 John Wiley & Sons, Ltd. [source] Catalytic and Surface-Electrocatalytic Water Oxidation by Redox Mediator,Catalyst Assemblies,ANGEWANDTE CHEMIE, Issue 50 2009Javier Alles in einem bieten die Assoziate aus ,Single-Site"-Wasseroxidationskatalysatoren (rot und blau) und Redoxvermittlern (grün und blau), die , sowohl in Lösung als auch über Phosphonatlinker an Metalloxidoberflächen gebunden , als stabile, robuste Katalysatoren für die Wasseroxidation wirken. Mehr als 28,000 Umsätze wurden mit einer Ladungseffizienz >95,% für die Sauerstoffproduktion ohne Abnahme der katalytischen Aktivität erreicht. [source] Catalytic and Heating Behavior of Nanoscaled Perovskites under Microwave RadiationCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 7 2008T. Krech Abstract Perovskite powders of the types La0.5Ca0.5AlyM1,yO3,, (y = 0,0.8), M = Fe, Cr, Mn, Co and LaxSr1,xMnyCo1,y (x = 0.5,1, y = 0,1) were prepared via a sol-gel route according to the modified Pechini method. Incineration of the resins was performed before final sintering at 1000,°C for 6,h. The phase composition of the samples was established by X-ray powder diffraction analysis, and the lattice parameters were calculated using Rietveld analysis. The shape and size of the particles were determined via scanning electron microscopy and the specific surface area of the powder perovskites was established by the BET method. The principal particles were ca. 100,nm in size and formed agglomerates larger than 1.0,,m. The composition of the perovskites was established by EDX analysis. Following this, the catalytic behavior was tested by means of total oxidation of propane. The catalytic performance was measured at atmospheric pressure with 3,g of catalyst in a fixed-bed quartz reactor (i.d. = 18,mm) under thermal-assisted and microwave-assisted conditions. Initial results show a strong dependence of the catalytic and heating behavior on the nature of the M-atom and its number of unpaired d-electrons as well as on the particle size and its specific surface area. No significant difference in the results could be detected from comparison of the two heating methods. [source] ChemInform Abstract: [Ir(COD)Cl]2 as a Catalyst Precursor for the Intramolecular Hydroamination of Unactivated Alkenes with Primary Amines and Secondary Alkyl- or Arylamines: A Combined Catalytic, Mechanistic, and Computational Investigation.CHEMINFORM, Issue 28 2010Kevin D. Hesp 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 Mild, Catalytic and Efficient Nazarov Cyclization Mediated by Phosphomolybdic Acid.CHEMINFORM, Issue 24 2010Kaliyappan Murugan 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: Catalytic, Asymmetric Cyanohydrin Synthesis in Propylene Carbonate.CHEMINFORM, Issue 46 2009Michael North 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, Asymmetric Michael Reactions of Cyclic Diketones with ,,,-Unsaturated ,-Ketoesters.CHEMINFORM, Issue 40 2009Michael A. Calter 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: A Catalytic and Enantioselective Synthesis of trans-2-Amino-1-aryltetralins.CHEMINFORM, Issue 35 2009Saumen Hajra 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, Asymmetric ,-Fluorination of Acid Chlorides: Dual Metal,Ketene Enolate Activation.CHEMINFORM, Issue 20 2009Daniel H. Paull 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 Conjugate Addition of Indoles to 4-Aryl-4-oxobut-2-enoates by FeCl3.CHEMINFORM, Issue 20 2009Xiaoxia Wang 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: Regioselective Synthesis of 2-(Arylthio)benzoates by the First Catalytic [3 + 3] Cyclocondensations of 3-(Arylthio)-1-(trimethylsilyloxy)-1,3-butadienes with 1,1,3,3-Tetramethoxypropane.CHEMINFORM, Issue 8 2009Muhammad Imran 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: Lewis Base Activation of Lewis Acids: Catalytic, Enantioselective Addition of Glycolate-Derived Silyl Ketene Acetals to Aldehydes.CHEMINFORM, Issue 42 2008Scott E. Denmark 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] Catalytic, Diastereoselective Allylation of Oshima,Utimoto Products.CHEMINFORM, Issue 28 2007Rebecca A. Duenes 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] Catalytic Conjugate Addition of Allyl Groups to Styryl-Activated Enones.CHEMINFORM, Issue 25 2007Joshua D. Sieber 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] Catalytic, Asymmetric Synthesis of 1,4-Benzoxazinones: A Remarkably Enantioselective Route to ,-Amino Acid Derivatives from o-Benzoquinone Imides.CHEMINFORM, Issue 13 2007Jamison Wolfer 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] Applications of Asymmetric Hydrosilylations Mediated by Catalytic (DTBM-SEGPHOS)CuH.CHEMINFORM, Issue 46 2006Bruce H. Lipshutz 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] Kinetic Resolution of 2-Oxazolidinones via Catalytic, Enantioselective N-Acylation.CHEMINFORM, Issue 39 2006Vladimir B. Birman 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] Catalytic, Asymmetric, "Interrupted" Feist,Benary Reactions.CHEMINFORM, Issue 9 2006Michael A. Calter 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] Stille Reactions Catalytic in Tin: A "Sn,F" Route for Intermolecular and Intramolecular Couplings.CHEMINFORM, Issue 25 2005William P. Gallagher Abstract For Abstract see ChemInform Abstract in Full Text. [source] A Catalytic and Iterative Route to ,-Substituted Esters via Highly Enantioselective Conjugate Addition of Dimethylzinc to Unsaturated Malonates.CHEMINFORM, Issue 33 2004Julia Schuppan Abstract For Abstract see ChemInform Abstract in Full Text. [source] An Auxiliary Induced Asymmetric Synthesis of Functionalized Cyclobutanes by Means of Catalytic [2 + 2]-Cycloaddition Reaction.CHEMINFORM, Issue 23 2004Kiyosei Takasu Abstract For Abstract see ChemInform Abstract in Full Text. [source] A New Catalytic Conjugate Addition/Aldol Strategy that Avoids Preformed Metalated Nucleophiles.CHEMINFORM, Issue 1 2004Kandasamy Subburaj No abstract is available for this article. [source] A Mild, Catalytic, and Highly Selective Method for the Oxidation of ,,,-Enones to 1,4-Enediones.CHEMINFORM, Issue 28 2003Jin-Quan Yu Abstract For Abstract see ChemInform Abstract in Full Text. [source] A Catalytic and ,-Selective Sialylation Using Novel 5-Azido Sialyl Fluoride.CHEMINFORM, Issue 18 2003Teruaki Mukaiyama No abstract is available for this article. [source] The Development of the First Catalyzed Reaction of Ketenes and Imines: Catalytic, Asymmetric Synthesis of ,-Lactams.CHEMINFORM, Issue 42 2002Andrew E. Taggi Abstract For Abstract see ChemInform Abstract in Full Text. [source] | ||||||||||||||||||||||||||||||||||||||||||||||