Electrochemical Acceptorless Dehydrogenation of N-Heterocycles: Sustainable Synthesis of Aromatic Compounds with Hydrogen Release

Electrochemical catalytic acceptorless dehydrogenation (ECAD) represents an emerging green organic transformation that enables the direct synthesis of unsaturated compounds. This work describes the first electrocatalyst-free and oxidant-free ECAD of N-heterocycles such as dihydropyrimidinones (DHPMs), dihydropyrimidines, and dihydropyridines (DHPs) under ambient conditions. By utilizing an undivided-cell configuration, various dihydro-heterocycles (40 examples in total) were effectively converted into the corresponding products with yields up to 99% at the anode, while generating molecular hydrogen at the cathode. Furthermore, the methodology demonstrated applicability to gram-scale synthesis, highlighting its scalability and industrial practicality. We present a mild, metal-free, and scalable strategy for constructing aromatic N-heterocycles, contributing to the advancement of sustainable organic synthesis.