An adaptable and efficient approach for the formation of C–N bonds using copper Schiff-base graphitic carbon nitride as a reusable and heterogeneous catalyst

Abstract

A mild, sustainable, environmentally friendly, one-pot synthesis method of C–N bonds using a reusable graphitic carbon nitrite-anchored copper Schiff base complex (Cu-SBg-C₃N₄) is described. To examine the catalytic activity of the synthesized Cu-SBg-C₃N₄, secondary amines and secondary amides were synthesized. Secondary amines, the desired product, were obtained with good-to-excellent yields (78–92%) at room temperature, whereas secondary amides were obtained with moderate-to-good yields (73–88%) at a higher temperature of 80 °C. Cu-SBg-C₃N₄, as a heterogeneous catalyst, shows remarkable recyclability, maintaining its catalytic activity and product yield through five consecutive runs without significant degradation. Additionally, the simple and easy catalyst preparation process, wide substrate scope, low cost, easy availability of the starting material, high selectivity, and avoidance of metal contamination are the main advantages of these protocols, and further gram-scale synthesis illustrates their industrial applications.