Electrocatalytic N–C–N coupling over a hierarchically ordered open single-atom superstructure toward organonitrogen synthesis

Electrochemically constructing C–N and N–C–N bonds provides an economical and sustainable alternative to conventional chemosynthesis. Herein, a hierarchically ordered open superstructure of N-doped carbon isolated with accessible three-coordinated Zn single-atom sites is explored for efficient electrocatalytic N–C–N coupling. Benefiting from the distinctive structural merits, this catalyst enables electrocatalytic preparation of N–C–N bonded compounds from methanol and amines. Notably, the Faradaic efficiency and selectivity of N,N,N’,N’-tetramethyldiaminomethane reach up to 77% and 96% at 0.8 V, respectively. Further integrating the aminoalkylation reaction, an electro-thermo cascade synthesis is explored with the electrochemically obtained N,N,N’,N’-tetramethyldiaminomethane serving as a unique reagent, leading to a specific set of organonitrogen compounds with (dimethylamino)methyl substituent, including topotecan hydrochloride, an anti-tumor drug, with a high yield of 95%. Furthermore, the in situ spectroscopic characterization and calculations unveil that the under-coordinated Zn-N₃ sites play a pivotal role in stabilizing the key *CH₂O intermediate, thereby facilitating subsequent nucleophilic addition with amines.