Electrochemically induced ring-opening/FriedelCrafts arylation of chalcone epoxides catalyzed by a triarylimidazole redox mediator.
J Org Chem
; 80(2): 781-9, 2015 Jan 16.
Article
em En
| MEDLINE
| ID: mdl-25458758
ABSTRACT
The indirect anodic oxidation of chalcone epoxides in the presence of electron-rich heteroarenes mediated by a triarylimidazole (Med) was investigated by cyclic voltammetry (CV) and controlled potential electrolysis. The CV results indicate that a homogeneous electron transfer between Medâ¢+ and chalcone epoxides is facilitated by an electron-rich heteroarene that serves as an arylation reagent. The preparative scale electrolysis generated epoxide-ring-opened/FriedelCrafts arylation products in moderate to good yields. The fact that only a catalytic amount of charge was required suggests that Medâ¢+ initiates a chain reaction. In addition, overoxidation of the products is avoided even though their oxidation potential is less than that of the starting chalcone epoxides.
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Base de dados:
MEDLINE
Assunto principal:
Oxirredução
/
Chalconas
/
Imidazóis
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article