Electrochemical nitration for organic C–N bond formation: a current view on possible N-sources, mechanisms, and technological feasibility

Abstract

Growing awareness of the environmental impact caused by the chemical industry drives considerations towards a circular economy and the use of renewable electricity. A key role will be played by ammonia (NH₃) currently produced in the Haber Bosch process at elevated temperature and pressure from fossil hydrogen leaving an enormous CO₂ footprint. A more sustainable production is to be realized by electrochemically generated hydrogen or all-electrochemical synthesis. Aside from the crucial role in fertilizer production, NH₃ is necessary for the synthesis of organic intermediates and monomers via C–N bond formation reactions. This perspective highlights different strategies for electrochemical C–N functionalisation focusing on electrophilic nitration. Based on literature from one century, syntheses involving different inorganic nitrogen sources are discussed and their potential is evaluated. Finally, a perspective for more sustainable electrochemical nitration using NH₃ and atmospheric nitrogen (N₂) is presented. This way, a possibility to bypass the Haber Bosch process shall be demonstrated especially for decentralized small-scale productions.