Recyclable Electron Transfer System: Electroreduction of Viologen in Ionic Liquids and Pd-catalyzed Reductive Coupling of Aryl Halides

Abstract

Electroreduction of N,N′-dioctyl-4,4′-bipyridinium (C₈V²⁺) bis(triflimide) was carried out in ionic liquids to give the corresponding quinoid C₈V⁰, which promoted reductive coupling of aryl halides in the presence of a Pd catalyst to give biaryls. C₈V²⁺ and the ionic liquids were used repeatedly.