Recent Development of Aryl Diazonium Chemistry for the Derivatization of Aromatic Compounds

Aryl diazonium salts are versatile building blocks in organic synthesis. In light of the ever-increasing importance of aryl diazonium salts spanning most disciplines of the chemical sciences, we review the recent development of aryl diazonium chemistry over the past seven years (2013–2020). Special emphasis is put on various new transformations involving the generation of radical intermediates via thermal, photochemical, and electrochemical means. Recent advances in the development of transition metal-catalyzed reactions using aryl diazonium salts are also reviewed. Together, these newly developed transformations significantly expand the synthetic chemist's repertoire of aromatic carbon–carbon and carbon–heteroatom bond forming methods using aryl diazonium precursors, providing powerful tools for the synthesis and modification of complex molecular scaffolds.