Harnessing redox properties of organic persistent radicals in SET-induced transformations

Organic persistent radicals are exceptionally versatile compounds known for their ability to undergo reversible oxidation and reduction. Their distinctive redox properties make them highly valuable in applications requiring reliable and predictable electron transfer. They exist in three stable redox states accessible through chemical or electrochemical oxidation and reduction processes. As such, organic persistent radicals can, in principle, serve as a platform for designing ground-state organic single-electron shuttle catalysts. This review highlights the unique chemistry of persistent radicals in mediating and promoting SET-induced transformations either in stoichiometric or catalytic settings. Particular emphasis is placed on persistent radical classes beyond nitroxides, such as TEMPO and its derivatives, which have historically dominated synthetic and catalytic applications.