Transient Stabilization Effect of CO<sub>2</sub> in the Electrochemical Hydrogenation of Azo Compounds and the Reductive Coupling of α‐Ketoesters
Yulei Zhao, Xuqiang Guo, Shuai Li, Yuhang Fan, Guo‐Cui Ji, Mengmeng Jiang, Yin Yang, Yuan‐Ye Jiang
Abstract
Abstract The carbon dioxide (CO 2 ) capture and utilization has attracted a great attention in organic synthesis. Herein, an unpresented transient stabilization effect (TSE) of CO 2 is disclosed and well applied to the electrochemical hydrogenation of azo compounds to hydrazine derivatives. Mechanistic experiments and computational studies imply that CO 2 can capture azo radical anion intermediates to protect the hydrogenation from potential degradation reactions, and is finally released through decarboxylation. The promotion effect of CO 2 was further demonstrated to work in the preliminary study of electrochemical reductive coupling of α‐ketoesters to vicinal diol derivatives. For the electrochemical reductive reactions mentioned above, CO 2 is indispensable. The presented results shed light on a different usage of CO 2 and could inspire novel experimental design by using CO 2 as a transient protecting group.