Search results for "Evolution theory"

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A molecular electron density theory study of the [3 + 2] cycloaddition reaction of nitrones with ketenes.

2017

The [3 + 2] cycloaddition (32CA) reaction between nitrones and ketenes has been studied within the Molecular Electron Density Theory (MEDT) at the Density Functional Theory (DFT) MPWB1K/6-311G(d,p) computational level. Analysis of the conceptual DFT reactivity indices allows the explanation of the reactivity, and the chemo- and regioselectivity experimentally observed. The particular mechanism of this 32CA reaction involving low electrophilic ketenes has been elucidated by using a bonding evolution theory (BET) study. It is determined that this reaction takes place in one kinetic step only but in a non-concerted manner since two stages are clearly identified. Indeed, the formation of the se…

Electron density010405 organic chemistryChemistryStereochemistryOrganic ChemistryRegioselectivity010402 general chemistryKinetic energy01 natural sciencesBiochemistryCycloaddition0104 chemical sciencesEvolution theoryComputational chemistryElectrophileDensity functional theoryReactivity (chemistry)Physical and Theoretical ChemistryOrganicbiomolecular chemistry
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A Molecular Electron Density Theory Study of the Reactivity of Azomethine Imine in [3+2] Cycloaddition Reactions

2017

The electronic structure and the participation of the simplest azomethine imine (AI) in [3+2] cycloaddition (32CA) reactions have been analysed within the Molecular Electron Density Theory (MEDT) using DFT calculations at the MPWB1K/6-311G(d) level. Electron localisation function (ELF) topological analysis reveals that AI has a pseudoradical structure, while the conceptual DFT reactivity indices characterise this TAC as a moderate electrophile and a good nucleophile. The non-polar 32CA reaction of AI with ethylene takes place through a one-step mechanism with low activation energy, 5.3 kcal/mol-1. A bonding evolution theory (BET) study indicates that this reaction takes place through a non-…

Models MolecularThiosemicarbazones[3+2] cycloaddition reactionsImineMolecular Conformationmolecular mechanismsazomethine iminePharmaceutical ScienceElectronsElectronic structureActivation energy010402 general chemistry01 natural sciencesArticlebonding evolution theoryAnalytical Chemistrychemistry.chemical_compoundNucleophileComputational chemistryDrug Discoveryconceptual density functional theoryMoleculeReactivity (chemistry)organic_chemistryelectron densityPhysical and Theoretical Chemistryazomethine imine; [3+2] cycloaddition reactions; molecular electron density theory; conceptual density functional theory; electron localisation function; bonding evolution theory; electron density; molecular mechanisms; chemical reactivityCycloaddition ReactionMolecular Structure010405 organic chemistrymolecular electron density theoryOrganic ChemistryCycloaddition0104 chemical scienceschemistryChemistry (miscellaneous)ElectrophileQuantum TheoryThermodynamicsMolecular MedicineDensity functional theoryImineselectron localisation functionAzo Compoundschemical reactivityMolecules; Volume 22; Issue 5; Pages: 750
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