Electrosynthesis of amides: Achievements since 2018 and prospects

Amide bond is not only the building block of proteins, peptides, and some synthetic polymers but is also commonly found in drugs, materials, and insecticides. Moreover, amides are vital intermediates for the synthesis of other types of molecules, including amines, isonitriles, and N-heterocycles. Nowadays, many techniques have been established for the synthesis of amide bonds, however, the majority of them depend on coupling reagents and an excess amount of base to neutralize the acids produced during the reaction. These methods are not only costly but also produce waste which is harmful to the environment. Due to the significance of amides, the development of methods for constructing amide bonds remains one of the most important tasks of organic synthesis. To develop green and sustainable routes for the preparation of amides, as well as to optimize conventional synthesis methods, more and more attention is being paid to the development of new synthetic routes using highly active intermediates generated by electrochemistry. The use of sustainable electricity to substitute chemical reagents is environmentally benign and would also establish new alternative synthetic routes. The purpose of this review is to demonstrate the continuous applications of electrosynthesis in the preparation of amides through relevant works reported from 2018 to the present.