Electrochemically driven reductive cyclization of o-nitroanilines: synthesis of 1,2-fused benzimidazoles and benzo[d]imidazoles

Saetan J.Purahong N.La-Ongthong K.Hassa N.Chotsaeng N.Kuhakarn C.Meesin J.Mahidol University2025-04-242025-04-242025-01-01Organic and Biomolecular Chemistry (2025)14770520https://repository.li.mahidol.ac.th/handle/123456789/109757The electrochemical synthesis of 1,2-fused benzimidazoles and benzo[d]imidazoles from o-nitroanilines in an undivided cell under constant current conditions was developed. The electrosynthesis proceeded through a tandem process involving nitro reduction/C(sp3)-H amination/condensation. The method can accommodate a broad range of o-nitroanilines and results in the desired products in yields of up to 99%. A plausible reaction mechanism was proposed on the basis of controlled experiments and cyclic voltammetry (CV) analysis. The benefits of the developed method include one-pot synthesis, open-air conditions, gram-scale synthesis and no requirement for a strong reductant.ChemistryBiochemistry, Genetics and Molecular BiologyElectrochemically driven reductive cyclization of o-nitroanilines: synthesis of 1,2-fused benzimidazoles and benzo[d]imidazolesArticleSCOPUS10.1039/d5ob00214a2-s2.0-105002741779