Efficient synthesis of organosulfur compounds via electrochemical biomass conversion

The formation of C–S bonds plays a pivotal role in the preparation of drug molecules and their intermediates. Utilizing an electrochemical method powered by renewable energy offers a sustainable pathway to produce organosulfur compounds but faces challenges, such as low Faradaic efficiency (<6.8%) and production rate (<10 µmol cm−2 h−1). Here we developed an efficient electrochemical approach to build C–S bonds and prepare a range of C–S species in high yield by coupling biomass oxidation with a sulfur-containing nucleophile using commercial catalysts. Taking methanol as a representative, we successfully synthesized hydroxymethanesulfonate, sulfoacetate and methanesulfonate. This system achieved a remarkable Faradaic efficiency of over 95% with a low current density below 10 mA cm−2. At commercial current densities ranging from 100 to 1,000 mA cm−2, the Faradaic efficiency remained consistently over 60% in a practical flow reactor with high production rates and stable operation over 50 h without significant voltage increases or yield decreases at 100 mA cm−2. Four reaction pathways, with *CH2O, *CH3 and *HOCH2CHO as key intermediates, have been identified to facilitate the C–S bond formation. This process can be extended to synthesize a wide range of organosulfur and organonitrogen compounds from diverse feedstocks, achieving impressive production rates. This approach is promising for the production of pharmaceuticals, textile chemicals and agrochemicals. This study presents an electrochemical approach to construct C–S bonds through the reaction of SO32− with electrophilic intermediates generated from the electrochemical oxidation of biomass derivatives, including methanol. This method achieves high Faradaic efficiencies and industrial-scale production rates of organosulfur compounds, such as hydroxymethanesulfonate, sulfoacetate and methanesulfonate.