Transition-Metal-Catalyzed Denitrative Coupling of Nitroarenes

Functionalization of arenes is a topic of central importance in diverse fields ranging from medicinal chemistry to materials science. Metal-catalyzed cross-coupling and nucleophilic aromatic substitution are among the most reliable methods to access functionalized arenes. In these reactions, haloarenes are often used as a versatile synthetic platform to introduce various functional groups. However, haloarenes are typically prepared from the corresponding nitroarenes through the classic sequence of reduction, diazotization, and halogenation. Thus, haloarene cross-coupling can become a multistep transformation overall. To avoid this lengthy sequence, the direct utilization of nitroarenes has the potential to significantly streamline synthetic processes and, therefore, has attracted attention in the chemistry community from the vantage points of atom- and step-economy. In this Review, we comprehensively cover advances in transition-metal-catalyzed denitrative reactions of nitroarenes.