A review on indole synthesis from nitroarenes: classical to modern approaches
Ajeet Chandra, Suresh C. Yadav, Subba Rao Cheekatla, Abhijeet Kumar
Abstract
-substituted nitroarenes has been achieved through methods such as Bartoli, Reissert, Cadogan, and Leimgruber-Batcho approaches. However, recent advancements have introduced novel one-pot and tandem strategies that effectively integrate redox and hydrogenation reactions to streamline indole formation. Emerging photochemical and electrochemical techniques have also enabled the selective conversion of nitroarenes into indoles bearing well-defined functional groups. Beyond their intrinsic biological activity, indoles serve as valuable intermediates for further derivatization into compounds such as isatins and oxindoles, expanding their synthetic potential. These advancements continue to enhance the synthetic toolkit for constructing biologically active indoles, with far-reaching applications in pharmaceuticals, agrochemicals, and advanced materials.