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Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/12657

Title: Peri-, Chemo-, Regio-, Stereo- and Enantio-Selectivities of 1,3-dipolarcycloaddition reaction of C,N-Disubstituted nitrones withdisubstituted 4-methylene-1,3-oxazol-5(4H)- one: A quantummechanical study
Authors: Pipim, George Baffour
Opoku, Ernest
Tia, Richard
Adei, Evans
Keywords: Density functional theory
Issue Date: 21-Jan-2020
Publisher: Elsevier Inc.
Citation: G.B. Pipim et al. / Journal of Molecular Graphics and Modelling 97 (2020) 107542. https://doi.org/10.1016/j.jmgm.2020.107542
Abstract: The peri-, chemo-, regio-, stereo- and enantio-selectivities of 1,3-dipolar cycloaddition reaction of C,N-disubstituted nitrones with disubstituted 4-methylene-1,3-oxazol-5(4H)-one have been studied usingdensity functional theory (DFT) at the M06e2X/6-311G (d,p) level of theory. The 1,3-dipole preferentiallyadds chemo-selectively across the olefinic bond in a (3þ2) fashion forming the corresponding spi-rocycloadduct. The titled reaction occurs with poor enantio- and stereo-selectivities, but a high degree ofregio-selectivity is observed for the addition of the 1,3-dipole across the dipolarophile. Electron-withdrawing groups on the dipolarophile significantly reduce the activation barriers while electron-donating groups on the dipolarophile increase the activation barriers. Analysis of the HOMO andLUMO energies of the two reacting species indicates that the 1,3-dipole reacts as a nucleophile while thedipolarophile reacts as the electrophile. Investigation of the electrophilic Parr function (PþKÞat the variousreaction centers in the dipolarophile indicates that the 1,3-dipole selectively adds across the atomicspecies with the largest electrophilic Mulliken and NBO atomic spin densities which is in accordancewith the energetic trends observed.
Description: An article published by Elsevier Inc. and also available at https://doi.org/10.1016/j.jmgm.2020.107542
URI: http://hdl.handle.net/123456789/12657
Appears in Collections:College of Science

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