Electrochemical processes can be used for “green” organic syntheses. They can help to reduce the need for oxidants or reductants and to minimize waste and improve atom economy. In addition, they are often simple to operate and easy to scale up. However, not all electrosynthesis approaches are necessarily more sustainable than conventional syntheses.
Aiwen Lei, Wuhan University and Jiangxi Normal University, Nanchang, both China, and Yong Yuan, Wuhan University, have discussed the advantages and limitations of electrosynthesis and aimed to provide guidance for the further development of electrosynthesis. The researchers point out that for redox reactions, organic electrosynthesis can often be greener than conventional methods that require stoichiometric amounts of oxidants or reductants. Oxidative cross-coupling reactions, for example, can avoid the waste usually produced by conventional coupling reactions while producing useful hydrogen gas.
However, the team has also considered the drawbacks of electrosynthesis, such as a need for hazardous or environmentally harmful electrolytes and additives, as well as a possible higher risk for fires or explosions. They also point out that the necessary equipment and membranes can be expensive, finding the right solvent can be tricky, and the use of metal-based catalysts can be challenging.
Overall, the researchers advise organic chemists to use electrosynthesis primarily in cases where traditional methods fail, to focus on finding improved methods and materials for electrosynthesis, and use electrolytes as sustainably as possible. They also point to opportunities for improvement in enantioselective reactions, reduction reactions, or synergistic reactions and state that more research attention should be focused on these fields.
- Is electrosynthesis always green and advantageous compared to traditional methods?,
Yong Yuan, Aiwen Lei,
Nat. Commun. 2020.
https://doi.org/10.1038/s41467-020-14322-z
