Browsing by Author "MESSAADIA, Sabir"

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    Modélisation moléculaire de l'influence de la polarité et de la nature électronique des substituants ur la réactivité et le mécanisme des réactions organiques
    (Université Badji Mokhtar Annaba, 2024) MESSAADIA, Sabir
    In this work we performed a computational investigation based on molecular electron density theory study of the [3+2] cycloaddition reaction of 5-oxo-2- (phenylmethylidene)pyrazolidin-2-ium-1-ide, a simple azomethine imine, with 3-nitro-2- phenyl-2H-chromene at the B3LYP/6-311G(d,p) computational level in order to find out the origin of the stereoselectivity experimentally observed. Analysis of reagents with electron localization function foresees a polar process; the energy profiles of the possible reactive pathways in gas phase and in solution of isopropanol confirm the high exo stereoselectivity and the complete ortho regioselectivity of the reaction experimentally observed. study of the most preferred pathway using some quantum chemistry tools such as quantum theory of atoms in molecules and the independent gradient model based on Hirshfeld distribution shows that the existance of several hydrogen bonds and van der Waals intermolecular noncovalent interactions are the factors favoring the ortho-exo selectivity. The bonding evolution theory study of the most favorable pathway reveals a two-stage one-step molecular mechanism.