Chiral Metal Salen Complexes as Chiral Electrocatalysts for Asymmetric Electrochemical Carboxylation of Acetophenone

Asymmetric electrochemical carboxylation is the direct and effective method to fix and utilize CO₂, and the selection of chiral catalysts is crucial. In this paper, a series of chiral metal salen complexes are prepared as chiral catalysts to achieve enantioselective conversion of acetophenone with CO₂ to synthesis chiral 2-hydroxy-2-phenylpropionic acid under electrochemical conditions. Under the catalysis of Ni^IIL1, the enantiomeric excess (ee) value of 90 % and yield of 59 % are obtained. By cyclic voltammetry and potentiostatic electrolysis, the effects of metal centers and tert-butyl groups in ligand structures on the catalytic results are studied and the possible reaction mechanism is proposed.