Homogeneous Electrocatalysis of the Trichloromethylphenylcarbinol Production by the Electroreduction of Chloroform and Benzaldehyde Mixed in Dimethylformamide

Galvanostatic electrolysis of a chloroform–benzaldehyde mixture in the cathodic space of a diaphragm cell (Pt cathode, C anode) filled with a 0.1 M Bu₄NBr solution in dimethylformamide yields trichloromethylphenylcarbinol. The benzaldehyde acts as both a prebase (intermediate radical anion of benzaldehyde deprotonates the chloroform) and an electrophilic agent. The interaction between benzaldehyde and the trichloromethyl anion yields an alcoholate, which in turn can deprotonate chloroform. The overall process occurs via a homogeneous-catalysis mechanism. Under certain conditions, the current efficiency for the target product reaches nearly 500%.