N,N-Dimethylation of nitrobenzenes with CO₂ and water by electrocatalysis

We have proposed a strategy for the synthesis of N,N-dimethylanilines from nitrobenzene and its derivatives, CO₂, and water via an electrochemical reaction under ambient conditions. H⁺ generated from H₂O was used as the hydrogen source. Pd/Co-N/carbon, in which the Pd nanoparticles were supported on Co-N/carbon, was designed and used as the electrocatalyst. It was found that the electrocatalyst was very efficient for the reaction in MeCN solution with 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Bmim]Tf₂N) as the supporting electrolyte and 1-amino-methylphosphonic acid (AMPA) as the thermal co-catalyst. A series of control experiments showed that Pd/Co-N/carbon and AMPA cooperated very well in accelerating the reaction. This synthetic route has some obvious advantages, such as using CO₂ and water as the reactants, ambient reaction conditions, and high yields of the desired products. This opens up a way to synthesize chemicals by the combination of an electrocatalyst and a thermal catalyst with organic compounds, CO₂, and water as the reactants.