Chemoselective electrochemical reduction of nitroarenes with gaseous ammonia

Valuable aromatic nitrogen compounds can be synthesized by reduction of nitroarenes. Herein, we report electrochemical reduction of nitroarenes by a protocol that uses inert graphite felt as electrodes and ammonia as a reductant. Depending on the cell voltage and the solvent, the protocol can be used to obtain aromatic azoxy, azo, and hydrazo compounds, as well as aniline derivatives with high chemoselectivities. The protocol can be readily scaled up to >10 g with no decrease in yield, demonstrating its potential synthetic utility. A stepwise cathodic reduction pathway was proposed to account for the generations of products in turn.

Automated summary

This study presents an electrochemical reduction method for nitroarenes using inert graphite felt as electrodes and ammonia as a reductant. By adjusting the cell voltage and solvent, different nitrogen-containing aromatic compounds can be selectively synthesized, and the reaction can be scaled up to over 10 grams with no decrease in yield. A stepwise cathodic reduction pathway is proposed to explain the generation of products.