Kaining Mao, Chenfei Liu, Yi Wang, Chaoxuan Gu, John M. Putziger, Nicholas I. Cemalovic, Cameron Muniz, Yue Qi & Song Lin
Published: 16 July 2025
DOI: 10.1038/s41586-025-09238-x
Nature
Electrochemistry is increasingly recognized as a powerful tool for expanding the scope and sustainability of organic synthesis. As a result, significant efforts have focused on developing asymmetric electrocatalytic reactions to access chiral molecules, which play key roles in biological systems. However, many electrochemical transformations proceeds via direct electrolysis without a catalyst, making enantiochemical control inherently challenging. Supporting electrolytes, essential for providing conductivity, can also affect both the rate and selectivity of electrochemical reactions. While chiral supporting electrolytes offer a promising avenue to achieve asymmetric transformations through direct electrolysis, their application in synthetic organic electrochemistry remains largely unexplored.
In this work, we report the use of chiral phosphate salts, employed in substoichiometric amounts as supporting electrolytes, to enable the asymmetric oxidation of racemic phosphines, affording enantioenriched phosphine oxide products. This method has shown excellent enantioselectivity and broad functional group tolerance. Our approach leverages a dynamic kinetic resolution strategy involving a rapid pyramidal inversion of an anodically generated phosphoniumyl radical cation. Concurrently, the high concentration of chiral phosphate anion at the electrode–electrolyte interface improves enantioselectivity during the rate-limiting chemical step. These findings illustrate the potential utility of chiral supporting electrolytes for advancing asymmetric transformations mediated by radical ions.