Chemical reactivity and regioselectivity investigation for the formation of 3,5-disubstituted isoxazole via cycloaddition [2 + 3] and antitrypanosomal activity prediction

Abstract

The antitrypanosomal activity of 3,5-disubstituted isoxazole has been investigated through molecular docking, revealing its binding to Plasmodium falciparum through seven hydrogen interactions demonstrating high affinity, supported by Molecular Dynamics Simulations. Followed by the Quantum Theory of Atoms in Molecules (AIM) studies, confirming the strength of hydrogen bonds and an acceptable ADMET profile has been found. The chemical reactivity of the cycloaddition [3 + 2] has been explored using Density Functional Theory (DFT). Results revealed a reverse electron demand, which was confirmed by global reactivity indices. Electron displacement was investigated based on Fukui functions, Methyl Cation Affinity (MCA), Methyl Anion Affinity (MAA), and Molecular Electrostatic Potential (MEP). The regioselectivity of the reaction was explored in the gas phase first and in dichloromethane secondarily to assess their impact on the reaction using the Integral Equation Formalism Polarizable Continuum (IEFPCM) model. Finally, additional bioactive compounds with 3,5-disubstituted isoxazole properties have been found using screening methods.