6533b831fe1ef96bd129972e

RESEARCH PRODUCT

A DFT study of the role of the Mg complex formation on the mechanism of the 1,3-dipolar cycloadditions of benzonitrile oxides with acryloylpyrazolidinone

Luis R. DomingoRachid JalalM. José AurellM. Esseffar

subject

Concerted reactionSubstituentRegioselectivityCondensed Matter PhysicsBiochemistryCycloadditionReaction ratechemistry.chemical_compoundBenzonitrilechemistryComputational chemistryPhysical and Theoretical ChemistrySolvent effectsDerivative (chemistry)

description

Abstract The role of the Mg complex formation on the mechanism, the reaction rate and regioselectivity of the 1,3-dipolar cycloaddition (13DC) reactions of benzonitrile oxides (BNOs) towards electron-deficient acryloylpyrazolidinones has been theoretically studied using DFT methods at the 6-31G* level. These 13DC reactions have asynchronous concerted mechanism with a non-polar character. These cycloadditions present a slight 5-regioselectivity induced by a steric repulsion between the phenyl substituent of the BNOs and the pyrazolidinone appendage present on the acryloyl derivative, which increases with the formation of the bulky Mg–acryloylpyrazolidinone complex. The present DFT study points out that the coordination of the Mg 2+ to the two oxygen atoms of the acryloyl derivative does not produce a discernible change in the mechanism and the reaction rate as a consequence of the non-polar character of these cycloadditions, but produces a regio- and stereoselective induction because of the hindrance produced by the bulk chiral magnesium complex. In this study the solvent effect is also examined.

yearjournalcountryeditionlanguage
2010-02-01Journal of Molecular Structure: THEOCHEM
https://doi.org/10.1016/j.theochem.2009.11.028