Search results for "C coupling"

showing 10 items of 149 documents

Dehydrogenative Anodic C−C Coupling of Phenols Bearing Electron‐Withdrawing Groups

2019

Abstract We herein present a metal‐free, electrosynthetic method that enables the direct dehydrogenative coupling reactions of phenols carrying electron‐withdrawing groups for the first time. The reactions are easy to conduct and scalable, as they are carried out in undivided cells and obviate the necessity for additional supporting electrolyte. As such, this conversion is efficient, practical, and thereby environmentally friendly, as production of waste is minimized. The method features a broad substrate scope, and a variety of functional groups are tolerated, providing easy access to precursors for novel polydentate ligands and even heterocycles such as dibenzofurans.

Denticityoxidation010405 organic chemistryChemistrySupporting electrolyteCommunicationC−C couplingoxygen heterocyclesSubstrate (chemistry)General Chemistry010402 general chemistryElectrochemistry01 natural sciencesEnvironmentally friendlyCombinatorial chemistryCommunicationsCatalysisCoupling reaction0104 chemical scienceschemistry.chemical_compoundElectrochemistry | Hot Paperelectrochemistrycross-couplingPolar effectPhenolsAngewandte Chemie International Edition
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A Next‐Generation Air‐Stable Palladium(I) Dimer Enables Olefin Migration and Selective C−C Coupling in Air

2020

Abstract We report a new air‐stable PdI dimer, [Pd(μ‐I)(PCy2 tBu)]2, which triggers E‐selective olefin migration to enamides and styrene derivatives in the presence of multiple functional groups and with complete tolerance of air. The same dimer also triggers extremely rapid C−C coupling (alkylation and arylation) at room temperature in a modular and triply selective fashion of aromatic C−Br, C−OTf/OFs, and C−Cl bonds in poly(pseudo)halogenated arenes, displaying superior activity over previous PdI dimer generations for substrates that bear substituents ortho to C−OTf.

Dimerchemistry.chemical_elementHomogeneous catalysisAlkylationmigration010402 general chemistry01 natural sciencesolefinCatalysisStyreneCatalysischemistry.chemical_compoundkatalyytitPolymer chemistryChemoselectivityOlefin fiber010405 organic chemistryCommunicationC−C couplingGeneral MedicineGeneral Chemistrypalladiumhomogeneous catalysisCommunications3. Good health0104 chemical scienceschemistrychemoselectivitykatalyysiddc:540Homogeneous Catalysis | Hot Paperolefin migrationPalladiumAngewandte Chemie International Edition
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Co-citation, bibliographic coupling and leading authors, institutions and countries in the 50 years of Technological Forecasting and Social Change

2021

[EN] Technological Forecasting and Social Change (TF&SC) is a leading international journal that publishes major advances related to technological forecasting and future studies. The journal was launched in 1969 and in 2019 celebrated its 50th anniversary. To celebrate 50 years of outstanding contributions, this study presents a bibliometric analysis of TF&SC publications and patterns of citations within TF&SC in terms of authors, institutions and countries. The analysis relies on the Web of Science Core Collection database for bibliographic content and Visualization of Similarities viewer software for mapping of bibliometric data. Our analysis identifies leading authors, universities and c…

ECONOMIA APLICADAFuture studiesBibliometric analysisWeb of science020209 energyLibrary science10 Technology 14 Economics 15 Commerce Management Tourism and Services02 engineering and technologyBibliometricsCo-citationManagement of Technology and InnovationPolitical science0502 economics and business0202 electrical engineering electronic engineering information engineeringBusiness and International ManagementApplied PsychologyVOS viewer05 social sciencesSocial changeCo-citationBibliographic couplingBibliometricsScience StudiesWeb of Science050203 business & managementTechnology forecasting
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Radical innovations: Between established knowledge and future research opportunities

2021

Abstract The fast growing body of radical innovation research is fragmented and difficult to overlook. We provide an overview of the most cited journals, authors, and publications and conduct a bibliographic coupling to structure the literature landscape. We identified the following research clusters: management of radical innovations, organizational learning and knowledge, financial aspects of radical innovation, radical innovation adoption and diffusion, radical industry innovations as challenges for incumbents, and radical innovation in specific industries. Based on an in-depth content analysis of these clusters, we identify the following future research opportunities: A systematic compi…

Economics and EconometricsKnowledge managementO03Bibliometric analysisCitation analysisManagement of Technology and Innovation0502 economics and businessddc:650AZ20-999Radical innovationBusiness and International ManagementModern portfolio theoryMarketingStructure (mathematical logic)H1-99business.industry05 social sciencesRegular ArticleCompetitor analysisBibliographic couplingBibliographic couplingSocial sciences (General)Futures studiesD83Citation analysisContent analysisOrganizational learning050211 marketingHistory of scholarship and learning. The humanitiesbusiness050203 business & managementJournal of Innovation & Knowledge
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Research on Emotion Recognition and Dementias: Foundations and Prospects

2021

Background: The study of emotion recognition could be crucial for detecting alterations in certain cognitive areas or as an early sign of neurological disorders. Objective: The main objective of the study is to characterize research development on emotion recognition, identifying the intellectual structure that supports this area of knowledge, and the main lines of research attracting investigators’ interest. Methods: We identified publications on emotion recognition and dementia included in the Web of Science Core Collection, analyzing the scientific output and main disciplines involved in generating knowledge in the area. A co-citation analysis and an analysis of the bibliographic couplin…

Family supportEmotionsBibliometrics050105 experimental psychology03 medical and health sciences0302 clinical medicineAlzheimer DiseasemedicineCluster AnalysisHumansDementia0501 psychology and cognitive sciencesGeneral Neuroscience05 social sciencesSign (semiotics)CognitionGeneral Medicinemedicine.diseaseBibliographic couplingEmotional RegulationFacial ExpressionPsychiatry and Mental healthClinical PsychologyAutismDementiaGeriatrics and GerontologyPsychologyFacial Recognition030217 neurology & neurosurgeryCognitive psychologyFrontotemporal dementiaJournal of Alzheimer's Disease
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Ephaptic coupling of myelinated nerve fibers

2001

Numerical predictions of a simple myelinated nerve fiber model are compared with theoretical results in the continuum and discrete limits, clarifying the nature of the conduction process on an isolated nerve axon. Since myelinated nerve fibers are often arranged in bundles, this model is used to study ephaptic (nonsynaptic) interactions between impulses on parallel fibers, which may play a functional role in neural processing.

Functional roleMaterials scienceMyelinated axonEphaptic couplingMyelinated nerve fiberNeural processingStatistical and Nonlinear PhysicsCondensed Matter PhysicsA delta fiberNeuroscienceNerve axonPhysica D: Nonlinear Phenomena
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3 Probing and Modelling of Galvanic Coupling Phenomena in Localized Corrosion

2011

The basic driving force of localized corrosion or corrosion protection in numerous cases is the galvanic coupling of which the dimensional aspect is fixed by a combination of scales regarding interfacial processes or properties. At the electrolyte–metal interface, it is necessary to consider the microstructure (including all real-time modification induced for example by applied stresses), the possible chemical changes at the surface of the material, and the electrolyte conductivity contribution, among others factors.

Galvanic corrosionMaterials scienceGalvanic couplingFriction stir weldingElectrolyteComposite materialConductivityMicrostructureBoundary element methodCorrosion
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Electroactive polymeric material with condensed structure on the basis of magnesium(II) polyporphine

2011

International audience; Previous publication of the authors presented evidences that electroch emical oxidation of Mg(II) porphine (fully unsubstituted porphyrin, MgP) in acetonitrile (AN) at a very low potential leads to deposition of films at electrode surface corresponding to typical electroactive polymers, with their reversible transition betwee n the electronconducting and insulating states depending on the electrode potential/oxidation level ("film of type I"). It is demonstrated in the actual publication that these films in contact with a monomer-free solution are subject to an irreversible transformation to quite a different material ("film of type II") under the influence of a high…

General Chemical EngineeringAnalytical chemistryInfrared spectroscopy02 engineering and technology010402 general chemistryElectrochemistry01 natural scienceschemistry.chemical_compoundTransition metalX-ray photoelectron spectroscopy[CHIM.ANAL]Chemical Sciences/Analytical chemistryelectroactive materialsElectrochemistryMolecule[CHIM.COOR]Chemical Sciences/Coordination chemistryconducting polymermagnesium porphineConductive polymer[CHIM.ORGA]Chemical Sciences/Organic chemistryelectropolymerization[CHIM.MATE]Chemical Sciences/Material chemistry021001 nanoscience & nanotechnology0104 chemical sciencesMonomerchemistryPhysical chemistryC-C coupling0210 nano-technologyunsubstituted porphyrinElectrode potentialElectrochimica Acta
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Local dynamic properties of the heme pocket in native and solvent-induced molten-globule-like states of cytochrome c

2002

We report the Soret absorption band, down to cryogenic temperature, of native and molten-globule-like state of horse heart cytochrome c. The band profile is analyzed in terms of vibronic coupling of the heme normal modes to the electronic transition in the framework of the Franck-Condon approximation. From the temperature dependence of the Gaussian broadening and of the peak position, we obtain information on the 'bath' of low frequency harmonic motions of the heme group within the heme pocket. The reported data indicate that, compared to the native state, the less rigid tertiary structure of the molten globule is reflected in a higher flexibility of the heme pocket and in greater conformat…

GlycerolProtein FoldingHot TemperatureCytochromeProtein ConformationBiophysicsCytochrome c GroupHemeProtein dynamicsBiochemistrychemistry.chemical_compoundMolten-globule proteinsNative stateSettore BIO/10HemeBinding SitesbiologySpectrum AnalysisProtein dynamicsOrganic ChemistryMolten globuleOptical absorption spectroscopyCrystallographyVibronic couplingchemistryAbsorption bandbiology.proteinMolten-globule proteins; Optical absorption spectroscopy; Protein dynamicsProtein foldingMathematics
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Electrochemical synthesis of carbazoles by dehydrogenative coupling reaction

2020

Abstract A constant current protocol, employing undivided cells, a remarkably low supporting electrolyte concentration, inexpensive electrode materials, and a straightforward precursor synthesis enabling a novel access to N‐protected carbazoles by anodic N,C bond formation using directly generated amidyl radicals is reported. Scalability of the reaction is demonstrated and an easy deblocking of the benzoyl protecting group is presented.

Green chemistry540 Chemistry and allied sciencesDeblocking filterSupporting electrolyteRadicalSustainable Chemistry010402 general chemistryElectrochemistry01 natural sciencesCatalysisCoupling reactionNC couplingProtecting groupgreen chemistry010405 organic chemistryChemistryCommunicationOrganic Chemistryheterocyclic chemistryGeneral ChemistryCombinatorial chemistryCommunications0104 chemical sciencesAnodecarbazoleselectrochemistry540 Chemie
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