Nanoarchitectonics of Sulfonated Boron Nitride for Catalytic Synthesis of Aromatic Nitriles under Mild Conditions

The development of sustainable protocols for synthesis of aromatic nitriles from corresponding alcohols using metal-free heterogenous catalysts is a challenging task. In this work, a highly versatile robust catalyst, sulfonated boron nitride (S-BN) has been reported for the synthesis of nitriles using aromatic alcohols and aqueous ammonia under environmentally benign mild conditions, wherein catalyst amount, time, temperature, and solvents have been optimized to achieve best yields. The S-BN catalyst was prepared by successive exfoliation and sulfonation of a low cost commercially purchased hexagonal boron nitride, which results in the generation of active centers onto the catalyst. The functionalized sulfonic groups impart acidic character to the catalyst which play a crucial role in synthesis of nitriles. The synthesis of nitriles using S-BN catalyst resulted in excellent yields with high turnover numbers. In addition, a wide substrate scope was examined for the developed reaction protocol and different green metric parameters were also calculated for a model reaction. An atom economy of 95% and E -factor of 0.11 were determined, which are highly desirable for green and sustainable reactions. Therefore, the use of S-BN catalyst for synthesis of nitriles reactions provides a green, sustainable, and metal-free methodology for the synthesis of aromatic nitriles under mild conditions.