Carbon dioxide (CO 2 ) is the largest contributor to the greenhouse effect, and fixing and using this greenhouse gas in a facile manner is crucial. This work investigates the electrocarboxylation of dichlorobenzenes with the atmospheric pressure of CO 2 in an undivided cell with an Ag cathode and an Mg sacrificial anode. The corresponding carboxylic acids and their derivatives, which are important industrial and fine chemicals, are obtained. To deeply understand this reaction, we investigate the influence of various reaction conditions, such as supporting electrolyte, current density, electric charge, and reaction temperature, on the electrocarboxylation yield by using 1,4-dichlorobenzene as the model compound. The electrochemical behavior of dichlorobenzenes is studied through cyclic voltammetry. The relation among the distinct electronic effects of dichlorobenzenes, the electrochemical characteristics of their reduction, and the distribution law of target products is also established.

Carbon dioxide (CO2) is regarded as an ideal C1 building block for the synthesis of value-added chemicals due to its low price, non-toxic, rich reserves, and recyclability. Organic electrosynthesis, using electricity as the driving force to avoid the use of toxic or expensive reducing agents, has become an efficient and environmentally friendly synthetic method and is widely used in the chemical conversion of CO2. In particular, the electro carboxylation reaction of CO2 with a substrate containing a specific group, such as C=O and C=N, can be realized to synthesize α-hydroxy acids, amino acids, and their derivatives under mild reaction conditions by accurately adjusting the current or potential. In this review, we focus on the recent advances in the electrocarboxylation of CO2 with unsaturated substrates (including ketones, aldehydes, and imines) in the past five years, which we hope could stimulate further research on electrocarboxylation of CO2 with ketones, aldehydes, and imines and provide a reference for the application of such reactions in green organic electrosynthesis in the future.