Iodide-mediated electrosynthesis of 2,6-dichlorobenzonitrile enhanced by acetate ions

An efficient indirect electrosynthesis method for the preparation of 2,6-dichlorobenzonitrile has been developed, utilizing iodide ions as a redox mediator in the presence of acetate ions. The experimental results demonstrate that the addition of OAc − ions significantly influences the electrochemical behavior of I − ions, primarily through the complexation of OAc − ions with I 2 and I + species. This complexation facilitates the formation of [I 2 OAc] − ions, which are readily oxidized at the anode to generate I + ions. These I + ions are subsequently stabilized by OAc − ions, forming highly electrophilic [IOAc 2 ] − species. This mechanism leads to an enhanced yield of 2,6-dichlorobenzonitrile in the iodide-mediated indirect electrosynthesis reaction. Furthermore, compared to previous systems employing chloride ions, the present method exhibits a higher cyanation yield, indicating that [IOAc₂]⁻ ions possess superior electrophilic activity relative to [ICl₂]⁻ ions, thereby promoting the efficient cyanation of 2,6-dichlorobenzaldehyde. The method also demonstrates broad applicability, achieving good yields with various aromatic aldehydes. These findings highlight the potential of this approach for the synthesis of aromatic nitriles, particularly in the indirect electrosynthesis of nitriles from their corresponding aldehyde precursors. This work provides a promising strategy for the development of sustainable and efficient electrochemical synthesis methods in organic chemistry.