Electrosynthesis and electrochemistry

Since the pioneering work of Kolbe, electrochemistry and electrosynthetic methods have been a part of the repertoire of the organic synthesis toolbox [1,2]. In general, only electrons are employed as reagents or the reagents are electrochemically regenerated. Consequently, waste can be avoided, and limited resources can be used in a careful and economic manner. Because alternative reaction pathways are employed by electrosynthetic methods, scarce and toxic elements can be replaced or are not required at all [3]. Moreover, in the foreseeable future regenerative sources of electricity, for example, photovoltaics and wind power, will provide a surplus of electricity as the current unsteady supply does not match the demand. Thus, the use of abundant electric power in electrosynthetic processes seems to be rational because high valorisation can be expected. Therefore, electrosynthesis fulfils all requirements for “green chemistry” [4]. When changing feed stocks and natural resources begin to play a more crucial role, electrosynthetic methodologies will not only be of ecological interest but also of economic significance. Unfortunately, the research in the past two decades was understated and considered as a niche methodology by the synthetic community. In addition, electrochemistry is mostly taught by physical chemists, which seems to create a natural barrier to preparative organic applications. However, the systematic use of cationic species as intermediates to avoid over-oxidation establishes new ways for functionalization of substrates and paves the way to novel synthetic tools [5-8].