Electrochemical substitution of hydrogen in ferrocene

Abstract

Interaction of radicals R . formed in anode decarboxylation of carboxylate anions with the ferricinium cation generated at the same electrode leads to alkylferrocene derivatives. A similar reaction of the ferricinium cation with radicals formed from dibasic acids or their semiesters yields esters of ferrocenyl- containing carboxylic ácids. Monosubstituted ferrocene, particularly those containing electron donor substituents, undergo further substitution to give di- and polysubstituted products. The procedures are described that lead to predominant isolation of either mono- or poly-substituted products. The results of qualitative and quantitative analyses of the polymethylation products show that orienting effects by the substituents are the same for radical substitution in the ferricinium cation and for electrophilic substitution in ferrocene.