The evaluation of chemoselectivity in multicomponent domino Knoevenagel/Diels-Alder reaction: A DFT study

Herein, the chemoselectivity of the multicomponent domino Knoevenagel/ Diels–Alder reaction is investigated in terms of theoretical calculations. The structures of reagents, transition states, intermediates and products are optimized at the M062X/6-31+G(d,p) level of theory. The reaction mechanism i...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Attarbashi Mina, Zabarjad Shiraz Nader, Samadizadeh Marjaneh
Formato: article
Lenguaje:EN
Publicado: Serbian Chemical Society 2021
Materias:
Acceso en línea:https://doaj.org/article/a9b6d897252342dc8f5c5cef8fc4162f
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
Descripción
Sumario:Herein, the chemoselectivity of the multicomponent domino Knoevenagel/ Diels–Alder reaction is investigated in terms of theoretical calculations. The structures of reagents, transition states, intermediates and products are optimized at the M062X/6-31+G(d,p) level of theory. The reaction mechanism involves processes of bond rotation, isomerization, asymmetric cycloaddition, acid–base and nucleophile–electrophile competitions, which are studied for the purpose of delivering a clear information of the mechanism in terms of chemoselectivity considerations. Accordingly, the chemoselectivity of the reaction is controlled by the releasing acetone during the decomposition of Meldrum acid in the presence of methanol and L-proline (G# = 61.45 kcal** mol-1). Comparing calculated results (gas and solvent phase) with the experimental ones showed that using these reagents are the kinetical favourite path for the chemoselective multicomponent cascade Knoevenagel/Diels–Alder reaction to produce the predominant product (>95 %). The results suggest that the creation of cis-spiro cyclohexanone is the predominant chemoselective product under kinetic control of the desired enone.