“Innocent” Electrolytes Can Influence Organic Electrosynthetic Selectivity

Organic electrosynthesis has emerged as a powerful strategy for leveraging electricity in organic synthesis. Despite its growing popularity, the fundamental molecular interactions governing electrochemical systems remain poorly understood. Many electrosynthetic reactions show strong dependence on the identity of the allegedly inert supporting electrolyte, which can significantly impact yields and selectivity, yet the physical origins of these effects are largely unexplored. A mechanistic understanding of electrolyte effects would enable more rational reaction design for applications. Here, we use cyclic voltammetry to investigate cobalt‐based metal–carbon bond homolysis and elucidate how common supporting electrolytes influence reaction rates. Bulk electrolysis experiments further reveal how electrolyte choice affects overall selectivity. Peak‐ratio analysis indicates that Co(Salen)–benzyl bond cleavage proceeds via a reversible homolysis mechanism that becomes rate‐limited by bond dissociation at high substrate concentrations. The reaction rate varies systematically with electrolyte identity, and changes in oxidative addition rates are quantified using simulations. These experimental findings are supported by ab initio and classical molecular dynamics simulations, as well as density functional theory calculations, which provide insights into reaction pathways, energetics, and dynamics. Together, these results demonstrate that electrolyte selection enables rational tuning of reaction rates and downstream selectivity, highlighting the critical role of electrolytes in metal‐catalyzed organic electrosynthesis.