Electrocatalytic Carboxylation of Arylic Bromides at Silver Cathode in the Presence of Carbon Dioxide

Abstract

A simple and efficient electrocatalytic carboxylation of arylic bromides has been developed using silver as cathode and magnesium as anode in N,N-dimethylformamide (DMF) under mild conditions. The influences of some key factors (such as the nature of cathode material, current density, and temperature) on this reaction were investigated. The investigations were extended to other arylic bromides under the optimized conditions, and the corresponding carboxylic acids were obtained in moderate to good yields (30–78%). The electrochemical behavior was studied at different electrodes (Ag, Cu, Ni, and Ti) by cyclic voltammetry, which showed significant electrocatalytic effect of the silver electrode toward the reductive carboxylation of arylic bromides.

Keywords:

• Arylic bromides
• CO₂
• electrocatalytic
• silver cathode

ACKNOWLEDGMENTS

This work was supported by the National Natural Science Foundation of China (20973065), Basic Research in Natural Science issued by Shanghai Municipal Committee of Science (08dj1400100), and Shanghai Leading Academic Discipline Project (B409).

Notes

^a General conditions: DMF = 10 mL, bromobenzene = 0.1 M, TBAI = 0.1 M, electric charge 2.5 F mol⁻¹, Mg as anode.

^b GC yield, based on the starting bromobenzene.

^a General conditions: Ag cathode, Mg anode, t = 0 °C.

^b GC yield, based on the starting arylic bromides.

^c This experiment (Table 1, entry 1) was repeated here for clarity.

^d Current density = 5 mA · cm⁻², electric charge = 2 F mol⁻¹.

^e Current density = 4 mA · cm⁻², electric charge = 2.5 F mol⁻¹.

^f Current density = 4.33 mA · cm⁻², electric charge = 2 F mol⁻¹.

^g Current density = 5 mA · cm⁻², electric charge = 2 F mol⁻¹.