Nanoarchitectonics of phosphorylated graphitic carbon nitride for Sustainable, selective and Metal-free synthesis of primary amides

Abstract Current strategies for the synthesis of primary amides from aldehydes requires expensive metal-based catalysts and high reaction temperature, which limits their potential applications. Herein, a highly selective, metal-free catalyst, phosphorylated graphitic carbon nitride (P-GCN) nanosheets is proposed for the amidation of aldehydes under ambient reaction conditions. The phosphorylation of graphitic carbon nitride (GCN) nanosheets via Arbuzov reaction leads to generation of Bronsted acidic sites onto the catalyst surface which behaves as active centers for the amidation reaction. The amidation reaction using P-GCN catalyst is carried out in environmentally benign solvents, eliminating the use of harsh toxic solvents. The detailed optimization of reaction parameters was done in order to attain high catalytic efficiency. The catalytic potential of P-GCN catalyst is investigated for a broad range of substrates demonstrating the versatility of the developed protocol. In addition to excellent recyclability, the sustainable nature of the developed protocol was examined using the Green metric parameters. The P-GCN catalyst exhibits excellent catalytic performance with high product yields and turnover numbers under optimized reaction conditions. Overall, the developed protocol for the amidation reaction using P-GCN nanosheets as a heterogeneous catalyst provides a useful and sustainable approach for the preparation of molecules of high significance.