[article] 
inIndustrial & engineering chemistry research > Vol. 49 N° 17 (Septembre 1, 2010) . - pp 8157–8163

Titre :	SO3H-functionalized ionic liquid catalyzed alkylation of catechol with tert-butyl alcohol
Type de document :	texte imprimé
Auteurs :	Xiaowa Nie, Auteur ; Xin Liu, Auteur ; Lei Gao, Auteur
Année de publication :	2010
Article en page(s) :	pp 8157–8163
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Ionic liquid Tert butyl alcohol.
Résumé :	Several SO3H-functionalized ionic liquids (FILs) were synthesized and their catalytic performances for catechol (CAT) alkylation with tert-butyl alcohol (TBA) were studied theoretically as well as experimentally. Under optimized reaction conditions, the conversion of CAT was 41.5%, and the selectivity for 4-tert-butyl catechol (4-TBC) could reach 97.1%. This electrophilic reaction exhibits a kinetics-dependent character. The higher frontier electron density at the C4 site, comparatively lower activation energy barrier (Ea), and higher thermodynamic stability all act in concert to make the reaction proceed preferentially toward 4-TBC. The FILs can lead to a much higher CAT conversion and a similar selectivity to 4-TBC compared to a Beta zeolite catalyst. Because the frontier electron density [fr(E)] of CAT was not significantly affected by the solvent, the product selectivity rule would not vary, whereas the addition of a solvent with a higher dielectric constant would slow the reaction by increasing Ea, thus resulting in a lower CAT conversion.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100800c

[article] SO3H-functionalized ionic liquid catalyzed alkylation of catechol with tert-butyl alcohol [texte imprimé] / Xiaowa Nie, Auteur ; Xin Liu, Auteur ; Lei Gao, Auteur . - 2010 . - pp 8157–8163.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 17 (Septembre 1, 2010) . - pp 8157–8163

Mots-clés :	Ionic liquid Tert butyl alcohol.
Résumé :	Several SO3H-functionalized ionic liquids (FILs) were synthesized and their catalytic performances for catechol (CAT) alkylation with tert-butyl alcohol (TBA) were studied theoretically as well as experimentally. Under optimized reaction conditions, the conversion of CAT was 41.5%, and the selectivity for 4-tert-butyl catechol (4-TBC) could reach 97.1%. This electrophilic reaction exhibits a kinetics-dependent character. The higher frontier electron density at the C4 site, comparatively lower activation energy barrier (Ea), and higher thermodynamic stability all act in concert to make the reaction proceed preferentially toward 4-TBC. The FILs can lead to a much higher CAT conversion and a similar selectivity to 4-TBC compared to a Beta zeolite catalyst. Because the frontier electron density [fr(E)] of CAT was not significantly affected by the solvent, the product selectivity rule would not vary, whereas the addition of a solvent with a higher dielectric constant would slow the reaction by increasing Ea, thus resulting in a lower CAT conversion.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100800c