Controlling One- or Two-Electron Oxidation for Selective Amine Functionalization by Alternating Current Frequency

Here, we report a unique electrosynthetic method that enables selective one-electron oxidation of tertiary amines to generate α-amino radical intermediates over the two-electron oxidation to iminium cations, providing easy access to arylation products by simply applying an optimal alternating current (AC) frequency. More importantly, we have discovered an electrochemical descriptor from cyclic voltammetry studies to predict the optimal AC frequency for various amine substrates, circumventing the time-consuming trial-and-error methods for optimizing reaction conditions. This new development in AC electrolysis provides an alternative strategy to solving challenging chemoselectivity problems in synthetic organic chemistry.