Electrocatalytic conversion of aromatic esters to ortho-aromatic ester amides using hydrophobic Cu-PTFE electrodes

Abstract

The hydrophobic Cu-PTFE electrodes were prepared using a composite plating method, with Cu as the substrate and PTFE nanoparticles suspended in the plating solution. The electrode properties, including phase composition, functional group changes, surface morphology, wettability, redox behavior, and electrochemical corrosion resistance, were characterized by different analytical ways, including XRD, FT-IR spectroscopy, scanning electron microscopy, contact angle measurements, and electrochemical tests. The results showed that based on the hydrophobicity of the Cu-PTFE electrode, the electrocatalytic reduction of 2-acetamidoaromatic esters with aromatic esters as substrates was carried out in up to 70 % yield using CH₃CN as solvent and reactant. In electrocatalytic reduction, CH₃CN can coordinate with oxygen, thereby stabilizing the ionic state of the reactants and lowering the reaction energy barrier. The high polarity solvent environment of CH₃CN can stabilize charged intermediates and promote nucleophilic attacks, and similar to Beckmann rearrangement reaction was realized to the coupling of adjacent C-N bonds and reduces the occurrence of side reactions. In addition, the use of hydrophobic electrodes as catalysts not only improves reaction efficiency but also conforms to the principles of green chemistry in its electron transfer process.