CSA@g-C(3)N(4) as a novel, robust and efficient catalyst with excellent performance for the synthesis of 4H-chromenes derivatives

A pioneering robust and green heterogeneous acidic catalyst (CSA@g-C(3)N(4)) was rationally designed via immobilization of camphorsulfonic acid (CSA) on the g-C(3)N(4) surface under mild conditions. Grafting CSA in the g-C(3)N(4) lattice is distinguished as the root cause of facilitating the structure change of g-C(3)N(4), leading to a unique morphology, accordingly the remarkable catalytic efficiency of CSA@g-C(3)N(4). The morphology of new as-prepared nano-catalyst was specified by means of FT-IR, XRD, SEM, EDS, TEM, TGA, and BET. For the first time, it is exhibited that the efficient catalyst CSA@g-C(3)N(4) can productively accomplish the three-component reactions with high yields and also serve as an inspiration for easily performing various sorts of MCRs based on our finding. The recommended synthesis pathway of chromenes derivatives is facile and cost-effective which applies a condensation reaction of salicylaldehyde, thiophenol, and malononitrile followed by ready purification in a benign manner. Moreover, the CSA@g-C(3)N(4) nanocomposite can be promptly reused, illustrating no sensational decrease in the catalytic activity after ten times.