Diazonium Salts: Applications in Modern Bond Formations and Classical Named Reactions

ABSTRACT Diazonium salts are remarkable intermediates and building blocks in synthetic organic chemistry and have developed into valuable partners in cross‐coupling reactions. By virtue of their ability to generate radicals, participation in metal‐catalyzed cross‐coupling as well as photoredox reactions etc., they enable in both construction of carbon‐heteroatom and carbon‐carbon bonds. Since their discovery by Peter Griess in 1858, numerous classical transformations have been developed over the years. In this particular review article, we provide a comprehensive overview of aryldiazonium salts as electrophilic coupling partners in modern organic synthesis. The discussion begins with the fundamental reactivity patterns of aryldiazonium salts and their mechanistic behavior. Subsequently, recent developments in C─C and C‐heteroatom bond‐forming reactions are being highlighted, with particularly emphasis on transition‐metal catalysis, photoredox catalysis, metal‐free methodologies, electrochemical approaches, and sustainable reaction platforms. Finally, the last revisits key organic named reactions involving diazonium salts from a modern perspective to illustrate their continuing significant medicinal and other applications in contemporary synthetic chemistry.