Search results for "Boron atom"

showing 2 items of 2 documents

A DFT study for the regioselective 1,3-dipolar cycloadditions of nitrile N-oxides toward alkynylboronates

2003

Abstract The mechanism for the 1,3-dipolar cycloaddition of benzonitrile oxide toward ethynyl and propynylboronate has been studied by using density functional theory (DFT) at B3LYP/6-31G* level. These cycloadditions are concerted [3+2] processes. The presence of the two oxygens on the boronic ester precludes the participation of the boron atom on [3+3] processes. The two regioisomeric channels associated to the formation of the isoxazoles bearing the boronic ester unit on the 4- or 5-positions have been characterized. The B3LYP/6-31G* activation parameters are in acceptable agreement with the experiments, allowing to explain the factors controlling these regioselective cycloadditions.

NitrileStereochemistryOrganic ChemistryOxideRegioselectivityBoron atomBiochemistryMedicinal chemistryCycloadditionchemistry.chemical_compoundDipoleBenzonitrilechemistryDrug DiscoveryDensity functional theoryTetrahedron
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Symmetric Fluoroborate and its Boron Modification: Crystal and Electronic Structures

2019

Four boron-carrying molecules were synthesized and purified. These were found to be (a) relatively neutral with respect to the parent BF derivative and (b) functionalized by donor&ndash

Steric effectsinorganic chemicalsfluroboratesElectron densityMaterials scienceGeneral Chemical Engineeringchemistry.chemical_element010402 general chemistry01 natural sciencesInorganic ChemistryCrystalchemistry.chemical_compoundMoleculeGeneral Materials Scienceelectron densityBoron010405 organic chemistrycharge transferCharge (physics)RSBICondensed Matter PhysicsBoron atom0104 chemical sciencesCrystallographychemistryanalogs of BODIPY dyesDerivative (chemistry)Crystals
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