NUK - logo
E-viri
Celotno besedilo
Recenzirano
  • Electrons and Holes as Cata...
    Francke, Robert; Little, R. Daniel

    ChemElectroChem, September 2, 2019, Letnik: 6, Številka: 17
    Journal Article

    The injection (or removal) of electrons into (or from) a substrate by an electrode can effectively catalyze various redox‐neutral reactions that otherwise require harsh conditions and/or the use of reagents. Such processes involve the electrogeneration of an ionic or radical ionic species, which after a coupled chemical step either undergoes a backward electron exchange with the electrode (ECEb mechanism) or triggers a chain process in the bulk solution. Under these circumstances, sub‐stoichiometric amounts of charge are sufficient to achieve a full conversion and conceptionally, the electrons and holes can be understood as being catalysts. This principle has been successfully applied to accomplish a number of redox‐neutral transformations such as molecular rearrangements, Diels‐Alder‐type cycloadditions and radical substitution reactions (SRN1) in a mild and atom‐economical fashion. Although examples have been reported but sporadically since the early 1970s, a number of exciting recent developments have led us to review and discuss these cases using unifying mechanistic concepts that are described herein. Role reversal: To most electrochemists, the term ‘electrocatalysis’ is known as the facilitation of a heterogeneous electron transfer by a chemical interaction between the electrode and a substrate. The opposite case, the utilization of a heterogeneous electron exchange to catalyze a chemical reaction, is a much less known but yet a very powerful approach in electrosynthesis. This remarkable strategy has been applied to a number of organic reactions and the goal of this Minireview is to discuss these cases using unifying mechanistic concepts.