C–H activation reactions of nitroarenes: current status and outlook

Ring substitution reactions of nitroarenes remain an under-developed area of organic synthesis, confined to the narrow domains of S_NAr and S_NArH reactions. While searching for alternative methodologies, we took stock of the C–H activation reactions of nitroarenes which unearthed a variety of examples of nitro directed regioselective C–H functionalization reactions such as ortho-arylation, -benzylation/alkylation, and -allylation, oxidative Heck and C–H arylation reactions on (hetero)aromatic rings. A collective account of these reactions is presented in this review to showcase the existing landscape of C–H activation reactions of nitroarenes, to create interest in this field for further development and propagate this strategy as a superior alternative for ring substitution reactions of nitroarenes. The prospect of merging the C–H activation of nitroarenes with C–NO₂ activation, thereby harnessing NO₂ as a transformable multitasking directing group, is also illustrated.