Explaining the selectivities and the mechanism of [3+2] cycloloaddition reaction between isoalantolactone and diazocyclopropane

Anas Ouled Aitouna; Ali Barhoumi; Habib El Alaoui El Abdallaoui; Noureddine Mazoir; Mohammed Elalaoui Belghiti; Asad Syed; Ali H Bahkali; Meenakshi Verma; Abdellah Zeroual

doi:10.1007/s00894-023-05688-0

Explaining the selectivities and the mechanism of [3+2] cycloloaddition reaction between isoalantolactone and diazocyclopropane

J Mol Model. 2023 Aug 15;29(9):280. doi: 10.1007/s00894-023-05688-0.

Authors

Affiliations

¹ Molecular Modeling and Spectroscopy Research Team, Faculty of Science, Chouaïb Doukkali University, P.O. Box 20, 24000, El Jadida, Morocco.
² Laboratory of Bioorganic Chemistry, Department of Chemistry, Faculty of Sciences, Chouaïb Doukkali University, P.O. Box 20, 24000, El Jadida, Morocco.
³ Laboratory of Physical Chemistry of Materials, Ben M'Sick Faculty of Sciences, Hassan II University, P.O. Box 7955, Casablanca, Morocco.
⁴ Laboratory of Nernest Technology, 163 Willington Street, Sherbrooke, QC, J1H5C7, Canada.
⁵ Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia.
⁶ University Centre for Research & Development, Department of Chemistry, Chandigarh University, Gharuan, Mohali, India.
⁷ Molecular Modeling and Spectroscopy Research Team, Faculty of Science, Chouaïb Doukkali University, P.O. Box 20, 24000, El Jadida, Morocco. zeroualabdellah2@gmail.com.

PMID: 37581864
DOI: 10.1007/s00894-023-05688-0

Abstract

Context: [3+2] cycloaddition processes between isoalantolactone (ISALL) and diazocyclopropane (DCYP), have been surveyed exercising the MEDT, reactivity indices, reactions, and activation energies, are computed. In an investigation of conceptual DFT indices, DCYP behaves as a nucleophile in this reaction, whereas ISALL acts as an electrophile. This cyclization is stereo-, chemo-, and regiospecific, as demonstrated by the activation and reaction energies, in clear agreement with the experiment's results. The mechanism for this [3+2] cycloaddition is occurring in two steps, according to ELF analysis.

Methods: For the purposes of this investigation, all computations were performed using the Gaussian 09 program. The optimization was completed using Berny's computational gradient optimization approach with the basis set 6-311G(d,p) and wB97XD functional. Frequency computations were utilized to characterize and locate stationary points where the transition phases have just one imaginary frequency and all frequencies for the reactants and products are positive. After evaluating the effect of dichloromethane (DCM) as a reaction solvent, the stationary point optimization was updated using the polarizable continuum model (PCM) developed by the Tomasi team. The electron localization function (ELF) has been examined within the context of topological investigations using Multiwfn software with a 0.05 grid step.

Keywords: Diazocyclopropane; ELF; Isoalantolactone; MEDT; Regiospecific.