title: Electrochemically induced ring-opening/Friedel–Crafts arylation of chalcone epoxides catalyzed by a triarylimidazole redox mediator.
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 Med•+ and chalcone epoxides is facilitated by an electron-rich heteroarene that serves as an arylation reagent. The preparative scale electrolysis generated epoxide-ring-opened/Friedel–Crafts arylation products in moderate to good yields. The fact that only a catalytic amount of charge was required suggests that Med•+ 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.
authors.forename: Nan-ning
authors.initials: NN
authors.lastname: Lu
authors.forename: Ni-tao
authors.initials: NT
authors.lastname: Zhang
authors.forename: Cheng-Chu
authors.initials: CC
authors.lastname: Zeng
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Hu
authors.forename: Seung Joon
authors.initials: SJ
authors.lastname: Yoo
authors.forename: R Daniel
authors.initials: RD
authors.lastname: Little
mesh_terms: D002384:Catalysis; D047188:Chalcones / Q000737:chemistry*; D004852:Epoxy Compounds; D007093:Imidazoles / Q000737:chemistry*; D015394:Molecular Structure; D010084:Oxidation-Reduction
chemical_list: D047188:Chalcones; D004852:Epoxy Compounds; D007093:Imidazoles; C028770:chalcone epoxide