Search results for "Catalysis"

showing 10 items of 5944 documents

A General and Efficient Method for the Monohydroxylation of Alkanes

1996

ChemistryGeneral MedicineGeneral ChemistryCatalysisAngewandte Chemie International Edition in English
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Ligand Effects in Grignard Additions

1992

ChemistryGeneral MedicineGeneral ChemistryLigand (biochemistry)Medicinal chemistryCatalysisAngewandte Chemie International Edition in English
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Synthesis of Deoxy Sialyl Lewisx Analogues, Potential Selectin Antagonists

1994

ChemistryGeneral MedicineGeneral ChemistryPharmacologyCatalysisSelectinAngewandte Chemie International Edition in English
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ChemInform Abstract: Gold(I)-Catalyzed Reactions of 1-(ortho-Alkynylaryl)ureas: Highly Selective Heterocyclization and Synthesis of Mixed N,O-Acetals.

2014

Treatment of alkynylureas (I) with trifluoroethanol in the presence of a Au/Ag catalytic system provides N-6-exo-dig heterocyclization products (III) and in some cases open chain acetals as side products.

ChemistryGeneral MedicineHighly selectiveMedicinal chemistryCatalysisChemInform
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Cer(IV)-katalysierter Einelektronen-Transfer (SET) von Acenaphthen und 1,4-Dihydronaphtho-[1,8-de][1,2] diazepin: Chemischer Nachweis unterschiedlich…

1987

ChemistryGeneral MedicineMedicinal chemistryCatalysisAngewandte Chemie
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ChemInform Abstract: Gold-Catalyzed Povarov-Type Reaction of Fluorinated Imino Esters and Furans.

2016

A gold-catalyzed Povarov-type reaction of fluorinated imino esters and furans is described. The process, which takes place in dichoromethane at room temperature, gives rise to novel fluorinated tetrahydrofuran-fused tetrahydroquinolines in good yields and moderate levels of diastereoselectivity in a very simple manner. The reported examples expand the versatility of the Povarov reaction to unprecedented fluorinated substrates, generating scaffolds that contain quaternary α-amino acid units.

ChemistryGeneral MedicinePovarov reactionCombinatorial chemistryCatalysisChemInform
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ChemInform Abstract: A Non-Catalyzed Ring-Opening Aminolysis Reaction of Sesquiterpene Lactones.

2010

Abstract Santonin (1) and other sesquiterpene lactones (6–10) react cleanly with pyrrolidine at room temperature to afford γ-hydroxyalkylamides, which by elimination with mesyl chloride in pyridine-benzene at 80°C give unsaturated alkylamides.

ChemistryGeneral MedicineRing (chemistry)SesquiterpeneChloridePyrrolidineCatalysisTerpenechemistry.chemical_compoundAminolysismedicineOrganic chemistrymedicine.drugSantoninChemInform
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On-Surface Synthesis of Unsaturated Carbon Nanostructures with Regularly Fused Pentagon–Heptagon Pairs

2020

Multiple fused pentagon-heptagon pairs are frequently found as defects at the grain boundaries of the hexagonal graphene lattice and are suggested to have a fundamental influence on graphene-related materials. However, the construction of sp2-carbon skeletons with multiple regularly fused pentagon-heptagon pairs is challenging. In this work, we found that the pentagon-heptagon skeleton of azulene was rearranged during the thermal reaction of an azulene-incorporated organometallic polymer on Au(111). The resulting sp2-carbon frameworks were characterized by high-resolution scanning probe microscopy techniques and feature novel polycyclic architectures composed of multiple regularly fused pen…

ChemistryGraphene530 PhysicsCommunicationAromaticityGeneral ChemistryElectronic structureAzulene010402 general chemistry01 natural sciencesBiochemistryCatalysis0104 chemical scienceslaw.inventionchemistry.chemical_compoundScanning probe microscopyCrystallographyColloid and Surface ChemistrylawLattice (order)540 ChemistryGrain boundaryHeptagonPhysics::Chemical PhysicsJournal of the American Chemical Society
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Mono- and Tripodal Porphyrins: Investigation on the Influence of the Number of Pyrene Anchors in Carbon Nanotube and Graphene Hybrids.

2020

A series of molecular precursors, containing one (1 and 3) or three (2 and 4) pyrene anchors, covalently linked to porphyrins (free base or Zn), were prepared and characterized. All of them enable ...

ChemistryGrapheneFree baseGeneral ChemistryCarbon nanotubeBiochemistryCatalysislaw.inventionchemistry.chemical_compoundColloid and Surface ChemistryCovalent bondlawPolymer chemistryPyreneJournal of the American Chemical Society
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Tuning the Magnetic Properties of Carbon by Nitrogen Doping of Its Graphene Domains

2015

Here we present the formation of predominantly sp-coordinate carbon with magnetic- and heteroatom-induced structural defects in a graphene lattice by a stoichiometric dehalogenation of perchlorinated (hetero)aromatic precursors [hexachlorobenzene, CCl (HCB), and pentachloropyridine, NCCl (PCP)] with transition metals such as copper in a combustion synthesis. This route allows the build-up of a carbon lattice by a chemistry free of hydrogen and oxygen compared to other pyrolytic approaches and yields either nitrogen-doped or -undoped graphene domains depending on the precursor. The resulting carbon was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM…

ChemistryGrapheneScanning electron microscopeInorganic chemistryGeneral Chemistry7. Clean energyBiochemistryCatalysis3. Good healthlaw.inventionMagnetizationsymbols.namesakeColloid and Surface ChemistryX-ray photoelectron spectroscopylawTransmission electron microscopysymbolsCarbide-derived carbonPhysical chemistryPyrolytic carbonRaman spectroscopyCHEMICAL-VAPOR-DEPOSITION; N-DOPED GRAPHENE; RECENT PROGRESS; FILMS; ELECTROCATALYSTS; NANORIBBONS; RADICALS; STATE
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