Search results for "Reaction"

showing 10 items of 6134 documents

Synthesis and NMR configurational study of imidazo[2,1-b]thiazoles from 1H-1,4-diazepine-7(6H)-thiones

1993

Abstract A thermal intramolecular cyclization of 1-vinyl2,3-dihydro-3 H -imidazole-2-thiones to imidazo[2,1-b]thiazoles is reported. A heteronuclear correlation study of these systems was made in order to establish the configuration of the products.

chemistry.chemical_compoundDiazepineBicyclic moleculeHeteronuclear moleculechemistryIntramolecular reactionStereochemistryOrganic ChemistryDrug DiscoveryIntramolecular cyclizationNuclear magnetic resonance spectroscopyBiochemistryTetrahedron
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Linear free energyortho-correlations in the thiophene series. Part IX . Kinetics of esterification with diazodiphenylmethane of some 3-, 4-, and 5-su…

1981

The rate constants for the esterification of some 3-, 4-, and 5-substituted thiophene-2-carboxylic acids with diazodiphenylmethane in methanol at 25° have been measured. The reactivity of some para- and ortho-substituted benzoic acids has also been determined. Logarithmic kinetic constants for ortho-, meta-, and para-like substituted thiophene-2-carboxylic acids furnish an excellent linear free energy relationship when plotted versus Δpka (β 0.89, r 0.989, C.L. > 99.9%, n 18, i 0.04), thus confirming the peculiar behaviour of five-membered ring derivatives. The correlation with σH values offers an additional proof of the hyper-ortho character of the 2,3-relation in thiophene derivatives. pa…

chemistry.chemical_compoundDiazodiphenylmethaneReaction rate constantChemistryOrganic ChemistryKineticsThiopheneOrganic chemistryReactivity (chemistry)MethanolFree-energy relationshipRing (chemistry)Medicinal chemistryJournal of Heterocyclic Chemistry
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Optimization Strategies for the Anodic Phenol‐Arene Cross‐Coupling Reaction

2021

chemistry.chemical_compoundElectrolysisMaterials sciencechemistrylawInorganic chemistryElectrochemistryPhenolCatalysisCoupling reactionAnodelaw.inventionChemElectroChem
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ChemInform Abstract: Reactions of Pyrano(3,4-b)indol-3-ones with Dienophiles: Consecutive (4 + 2) Cycloaddition/Cycloreversion/1,2 Elimination.

1990

Methylpyrano[3,4-b]indol-3-ones 1 react with selected dienophiles (as acetylene equivalents) in a consecutive Diels-Alder/cycloreversion/1,2 elimination reaction sequence to furnish the 1-methyl- and 1,4-dimethylcarbazoles 4.

chemistry.chemical_compoundElimination reactionAcetylenechemistryStereochemistryGeneral MedicineCycloadditionSequence (medicine)ChemInform
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Über die zersetzung von hydroperoxyden durch katalase und durch lebereiweißfraktionen

1959

Es werden Herstellung und Eigenschaften einer Eiweisfraktion aus Rinderleber beschrieben, die auf Wasserstoffperoxyd, athyl-, Isopropyl- und tert.-Butylhydroperoxyd zersetzende Wirkung ausubt. Der fur das Zustandekommen der Zersetzungsreaktion der drei letzgenannten Peroxyde notwendige Acceptor wird als athanol identifiziert. Die Eiweisfraktion wird bezuglich ihrer Eigenschaften mit einer kristallisierten Katalase verglichen und aus dem Ergebnis der Schlus gezogen, das sie mit Katalase identisch ist. Als Reaktionsprodukt der enzymatisch katalysierten Reaktion zwischen tert.-Butylhydroperoxyd und athanol wurde Acetaldehyd nachgewiesen. The preparation and properties of an albumen fraction fr…

chemistry.chemical_compoundEthanolchemistrybiologyCatalasePolymer chemistryAcetaldehydebiology.proteinHydrogen peroxideMedicinal chemistryChemical decompositionIsopropylReaction productDie Makromolekulare Chemie
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ChemInform Abstract: 1,7-Octadiene-Assisted Tandem Multicomponent Cross-Enyne Metathesis (CEYM)-Diels-Alder Reactions: A Useful Alternative to Mori′s…

2013

The protocol relies on a relay metathesis process, in which 1,7-octadiene acts as an in situ source of ethylene.

chemistry.chemical_compoundEthyleneTandemchemistryDiels alderSalt metathesis reactionGeneral MedicineEnyne metathesisMetathesisCombinatorial chemistryChemInform
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A Headful of T4 Coliphage DNA Packaged to Fasces-Like Globules in Fractal Models

1998

We present a new model for T4 DNA packaging based on fractal considerations. The proposed model is based on electron microscopic observations of spread and packaged DNA. The model takes into account enzymatically and unidirectionally driven packaging, and quick release of the DNA during infection. We also consider the different biochemical reactions of the packaging process.

chemistry.chemical_compoundFractalMaterials sciencechemistrybiologyBiophysicsActive packagingBiochemical reactionsColiphagebiology.organism_classificationElectron microscopicDna packagingDNA
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Synthesis of Novel Triazolopyridylboronic Acids and Esters. Study of Potential Application to Suzuki-Type Reactions.

2004

This paper describes a general method for the synthesis of novel [1,2,3]triazolo[1,5-a]pyridylboronic acids and esters, and the first results on Suzuki cross-coupling reactions with these new compounds and [1,2,3]triazolo[5,1-a]isoquinolylboronic acid, reacting with a variety of aryl halides as a route to 7-aryltriazolopyridines and 5-aryltriazoloisoquinolines.

chemistry.chemical_compoundGeneral methodSuzuki reactionChemistryArylOrganic ChemistryDrug DiscoveryOrganic chemistryHalideGeneral MedicineBiochemistryCombinatorial chemistryChemInform
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Asymmetric Aldol Reaction with Polystyrene-Supported Proline-Based Catalysts

2009

chemistry.chemical_compoundHajos–Parrish–Eder–Sauer–Wiechert reactionNitroaldol reactionAldol reactionchemistryOrganocatalysisOrganocatalysis proline supported-catalysts aldol reaction proline peptidesOrganic chemistryAldol condensationSettore CHIM/06 - Chimica OrganicaPolystyreneProlineLewis acid catalysisSynfacts
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Asymmetric aldol reaction in water catalyzed by polystyrene-supported proline

2007

chemistry.chemical_compoundHajos–Parrish–Eder–Sauer–Wiechert reactionchemistryAldol reactionOrganocatalysisOrganic chemistryPolystyreneProlineSettore CHIM/06 - Chimica OrganicaSupported organocatalystCatalysis
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