Atom-Economical Insertion of Hydrogen and Sulfur into Carbon-Nitrogen Triple Bonds Using H2S via Synergistic C-N Sites

Developing efficient strategies that convert industrial waste hydrogen sulfide (H2S) into value-added products is meaningful for both applied environmental science and industrial chemistry. Here we report a series of heterogeneous N-doped carbon catalysts with synergistic C-N sites that enable the nucleophilic addition of H2S into aromatic nitrile compounds (PhCN) under mild conditions to produce thiobenzamide (PhCSNH2). The as-designed C-N sites achieve a high thioamide production rate of 26400 μmolPhCSNH2/L·h and a notable selectivity of ca. 80% at 60 °C within a short 2-hour timeframe. Additionally, the catalyst exhibits easy recyclability and maintains high stability over ten cycles during a 6-month period. Systematic microscopic and in situ spectroscopic characterizations, combined with theoretical calculations, reveal that C-pyridinic N coordination sites effectively lower the adsorption energy barrier of the crucial intermediate *PhCSHNH, offering a dynamically favorable pathway for PhCSNH2 production. Furthermore, the protocol demonstrates excellent compatibility with various substituted substrates, providing access to a diverse range of thioamides.