Search results for "aromatic compound"

showing 3 items of 13 documents

Asymmetric synthesis of functionalized tetrahydrofluorenones via an NHC-catalyzed homoenolate Michael addition

2018

The first example of an N-heterocyclic carbene-catalyzed asymmetric desymmetrization of enal-tethered cyclohexadienones via an intramolecular homoenolate Michael addition/esterification reaction is described. This new protocol offers a direct entry to various functionalized tetrahydrofluorenones with three contiguous stereocenters in high yields, good diastereoselectivities and excellent enantioselectivities.

aromaattiset yhdisteet010402 general chemistry01 natural sciencesDesymmetrizationCatalysisStereocenterCatalysisDirect entryMaterials Chemistryta116kemiallinen synteesi010405 organic chemistryChemistryaromatic compoundsMetals and AlloysEnantioselective synthesisGeneral ChemistryCombinatorial chemistry0104 chemical sciencesSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsIntramolecular forceCeramics and CompositesMichael reactionEsterification reactionchemical synthesisChemical Communications
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Increased conformational rigidity of humic substances by oxidative biomimetic catalysis

2005

A synthetic water-soluble meso-tetra(2,6-dichloro-3-sulfonatophenyl)porphyrinate of iron(III) chloride, Fe(TDCPPS)Cl, was employed as a biomimetic catalyst in the oxidative coupling of terrestrial humic materials. High-performance size-exclusion chromatography (HPSEC), solid-state nuclear magnetic resonance (CPMAS-(13)C NMR), electron paramagnetic resonance (EPR), and diffuse reflectance infrared spectroscopy (DRIFT) were used to follow conformational and structural changes brought about in different humic materials by the oxidative coupling. Increase in apparent weight-average molecular weight (Mw(a)) occurred invariably for all humic substances with the oxidative polymerization catalyzed …

conformationMagnetic Resonance SpectroscopySpectrophotometry InfraredPolymers and PlasticsDiffuse reflectance infrared spectroscopy (DRIFT)Biomimetic materialsaromatic compoundgel permeation chromatographyMolecular ConformationPhotochemistryIron compoundslaw.inventionPolymerizationenvironmental managementcovalent bondlawSize exclusion chromatographyBiomimetic catalysisBiomimeticsMaterials ChemistryOrganic chemistryHumic acidElectron paramagnetic resonanceInfrared spectroscopyChromatography High Pressure Liquidchemistry.chemical_classificationSettore CHIM/03 - Chimica Generale e InorganicaCarbon IsotopesChromatographyindustryCatalystsChemistrytetra(2articleelectrophoretic mobilitybiomimetic materialNuclear magnetic resonance spectroscopyunclassified drugConformationsacetic acidpriority journalCovalent bondSpectrophotometrySynthesis (chemical)High Pressure Liquidtechnology6 dichloro 3 sulfonatophenyl)porphyrinic acid derivativeInfraredOxidation-Reductionmolecular stabilityHumic materialsoxidationSettore AGR/13 - Chimica AgrariaSupramolecular chemistryBioengineeringcomplex mixturesCatalysisCatalysisdiffuse reflectance spectroscopyhumic substanceBiomaterialsalkyl etherElectron spin resonance spectroscopycomplex formationParticle SizeNuclear magnetic resonance spectroscopyHumic Substancesfree radicalbiomimetic oxidative humicelectron spin resonanceHigh performance size exclusion chromatography (HPSEC)ferrous chloridemolecular weightsolid statecarbon nuclear magnetic resonancePolymerizationSolubilitychemical structureOxidative coupling of methaneCatalysts; Conformations; Electron spin resonance spectroscopy; Infrared spectroscopy; Iron compounds; Nuclear magnetic resonance spectroscopy; Oxidation; Polymerization; Size exclusion chromatography; Solubility; Synthesis (chemical); Biomimetic catalysis; Diffuse reflectance infrared spectroscopy (DRIFT); High performance size exclusion chromatography (HPSEC); Humic materials; Biomimetic materials; acetic acid; alkyl ether; aromatic compound; biomimetic material; ferrous chloride; free radical; tetra(26 dichloro 3 sulfonatophenyl)porphyrinic acid derivative; unclassified drug; article; carbon nuclear magnetic resonance; catalysis; catalyst; chemical structure; complex formation; conformation; covalent bond; diffuse reflectance spectroscopy; electron spin resonance; electrophoretic mobility; environmental management; gel permeation chromatography; humic substance; industry; molecular stability; molecular weight; oxidation; polymerization; priority journal; solid state; technology; Biomimetics; Carbon Isotopes; Catalysis; Chromatography High Pressure Liquid; Electron Spin Resonance Spectroscopy; Humic Substances; Magnetic Resonance Spectroscopy; Molecular Conformation; Oxidation-Reduction; Particle Size; Spectrophotometry Infraredcatalyst
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Multifacial Recognition in Binary and Ternary Cocrystals from 5-Halouracil and Aminoazine Derivatives

2018

A systematic analysis using single crystal X-ray diffraction was performed to explore the role exerted by potential intercomponent proton-transfer reactions in the supramolecular structures of A–B cocrystals formed by 5-haloderivatives of uracil (A), coupled with 2-aminoadenine simulants (aminoazines, B). Twelve new heterodimers were synthesized in different stoichiometries and cocrystallized by solvent cogrinding followed by solution crystallization. In the binary cocrystals, uracil or 1-methyluracil with halide modification at the 5 position (F, Cl, Br, I) was coupled with amino-aromatic N-heterocycles (melamine, 2,4,6-triaminopyrimidine, 2,6-diaminopyridine) as a multivalent site for pyr…

proton transferPyrimidineX ray diffractionSupramolecular chemistry010402 general chemistry01 natural sciencesaromatic compounds; hydrogen bonds; ionization; proton transfer; X ray diffractionNucleobaselaw.inventionchemistry.chemical_compoundlawionizationsingle crystal X-raysGeneral Materials ScienceCrystallizationta116orgaaniset yhdisteet010405 organic chemistryHydrogen bondChemistryaromatic compoundsUracilGeneral ChemistrykiteetCondensed Matter Physics0104 chemical sciencesCrystallographyhalogen bondinghydrogen bondsTernary operationSingle crystalCrystal Growth & Design
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