Oxygen Vacancy Boosts Nitrogen-Centered Radical Coupling Initiated by Primary Amine Electrooxidation
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2025-07-11 |
| Journal | ECS Meeting Abstracts |
| Authors | Mengwei Han, Yongxiang Luo, Leitao Xu, Wei Chen, Chengmei Li |
Abstract
Section titled āAbstractāNitrogen-centered radicals (NCRs) play a crucial role in organic synthesis. Compared with the traditional two-step synthesis of NCRs, the direct dehydrogenation of primary amines to synthesize NCRs has the advantages of atom economy and step economy. In the context of electrochemical N-N coupling systems, relatively little research has been done on more environmentally friendly aqueous electrolytes. The electrochemical primary amine oxidation reaction (ePAOR) on nickel-based catalysts represents an efficient and sustainable pathway for the oxidative dehydrogenation of primary amines in aqueous electrolytes to form NCRs. Nevertheless, ePAOR on nickel-based catalysts involves two hydrogen atom transfer (HAT) processes (the oxidative dehydrogenation of Ī±-C-H and N-H bonds). Primary amines with two Ī±-C-H bonds are not conducive to NCRs synthesis. Primary amines possessing one Ī±-C-H bond can serve as substrates for NCR synthesis, yet the electrooxidation process leads to the formation of unstable imine intermediates that readily hydrolyze, thereby restricting the effective utilization of NCRs. In this study, we present an electrochemical methodology for synthesizing NCRs for nitrogen-centered radical coupling reactions via ePAOR. Using NiO as the model catalyst, the N-N coupling selectivity was compromised due to the weak adsorption energy of the imine and the occurrence of hydrolysis side reactions. Guided by theoretical calculations, V O -NiO with oxygen vacancies was synthesized, which augments the adsorption capacity of imine so that it boosts nitrogen-centered radical coupling initiated by the ePAOR. Furthermore, the substrate scope was broadened and the N-N cross-coupling reaction system was developed by ePAOR on V O -NiO. We believe that this method can be widely applied to NCRs generation and free radical homo/cross-coupling reactions.