Harnessing the versatility of hydrazones through electrosynthetic oxidative transformations

Hydrazones are important structural motifs in organic synthesis, providing a useful molecular platform for the construction of valuable compounds. Electrooxidative transformations of hydrazones constitute an attractive opportunity to take advantage of the versatility of these reagents. By directly harnessing the electrical current to perform the oxidative process, a large panel of organic molecules can be accessed from readily available hydrazones under mild, safe and oxidant-free reaction conditions. This review presents a comprehensive overview of oxidative electrosynthetic transformations of hydrazones. It includes the construction of azacycles, the C(sp²)-H functionalization of aldehyde-derived hydrazones and the access to diazo compounds as either synthetic intermediates or products. A special attention is paid to the reaction mechanism with the aim to encourage further development in this field.