Electrocatalytic Alkene Hydrogenation/Deuteration

Traditional reductions of alkenes, such as using stoichiometric reductants with waste generation and catalytic hydrogenation with high-pressure H₂, are accompanied by environmental or safety issues. Herein, we demonstrated a universal method for the electrocatalytic hydrogenation and deuteration of alkenes with modified electrodes under ambient temperature. The key M-H/M-D species for alkene reduction were generated from the electrolysis of H₂O/D₂O on modified electrodes, which avoided the usage of H₂ and D₂. Mono-, di-, tri-, and tetra-substituted alkenes were successfully reduced in this electrocatalytic system using H₂O and D₂O as hydrogen and deuterium sources. Electron-donating/-withdrawing alkenes, alkenes with other easily reducible functional groups, and complicated natural products and drugs were all reductive hydrogenated and deuterated with excellent yields (85 examples, yields up to 99%). Faraday efficiency of this efficient method could reach 84%. Moreover, the catalytic amount of metal could decrease to less than 0.01 mol %.