Electroreduction Reactions Mediated by Organic Molecules: Recent Advances and Applications

Electroreduction is an important aspect of organic electrochemistry. Its chemistry does not require the addition of additional reductants, making it an effective alternative to various traditional reduction reactions. Among them, organo‐mediated electroreduction is recognized as a promising approach. Organo‐mediators can be reduced directly at the cathode to form reactive radical anions that subsequently reduce the substrate via electron transfer (ET) to initiate the reaction being investigated. Organo‐mediators typically have a more positive reduction potential, and their role in the whole reaction is similar to that of catalysts. Their addition transforms the ET process from the original heterogeneous process into a homogeneous one. Organo‐mediated electroreduction can effectively avoid the over‐electrolysis of the substrate and the product at the electrode and the intolerance of sensitive substrates or functional groups during electrolysis, thereby preventing the occurrence of side reactions. It can also prevent the excessive consumption of reagents and electrical energy while promoting the reaction to achieve higher or completely different selectivity. Considering the advantages of this type of reaction, this review will provide a detailed description of electroreduction reactions mediated by organic molecules in recent years and elucidate the mechanism of the organo‐mediators in the transformations.