Difluoro- and trifluoromethylation of electron-deficient alkenes in an electrochemical microreactor

Abstract

Electrochemical microreactors, which have electrodes integrated into the flow path, can afford rapid and efficient electrochemical reactions without redox reagents due to the intrinsic properties of short diffusion distances. Taking advantage of electrochemical microreactors, Kolbe electrolysis of di- and trifluoroacetic acid in the presence of various electron-deficient alkenes was performed under constant current at continuous flow at room temperature. As a result, di- and trifluoromethylated compounds were effectively produced in either equal or higher yields than identical reactions under batch conditions previously reported by Uneyamas group. The strategy of using electrochemical microreactor technology is useful for an effective fluoromethylation of alkenes based on Kolbe electrolysis in significantly shortened reaction times. In the flow! In an electrochemical microreactor, Kolbe electrolysis of acetic acid derivatives allows facile difluoro- and trifluoromethylation of electrondeficient alkenes. Compared with bulk reactions, higher yields are achieved at room temperature and in short reaction times. © 2014 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.