Visible‐Light‐Mediated Hydration of Benzonitriles Catalysed by Silver Nanoparticles on Triazine

ABSTRACT An eco‐friendly, visible‐light‐driven synthesis of benzamides from readily accessible benzonitriles is reported under heterogeneous conditions. A carbon‐rich material, such as polyhexahydrotriazine (PHT), graphene oxide (GO), graphitic nitride (g‐C 3 N 4 )or carbon black, was used as a novel support to stabilise silver nanoparticles (NPs). These silver NPs show remarkable catalytic activity in the hydration of nitriles under visible light irradiation (white light, 9 W). Furthermore, silver NPs stabilised by a triazine moiety exhibit better performance than other supported silver systems, including graphene oxide and carbon black. Their stability and heterogeneous nature as catalysts have been demonstrated through three cycles of recycling in the synthesis of benzamides. This approach utilises mild visible light and a recyclable catalyst that efficiently converts benzonitriles to amides in excellent yields. This work provides a sustainable approach to amide synthesis. Density functional theory (DFT) calculations further indicate that the binding energy of 4‐bromobenzonitrile (BCN) to Ag@C 3 N 4 is −31.50 kcal/mol. Further triphenyl phosphine poisoning test confirms the heterogeneous nature of our catalyst under visible light.