ZnS nanoparticles immobilized on graphitic carbon nitride as a recyclable and environmentally friendly catalyst for synthesis of 3-cinnamoyl coumarins

Zinc oxide nanoparticles immobilized on a graphitic carbon nitride (ZnS NPs/g-C 3 N 4 ) nanocomposite were applied as an organometallic recyclable catalyst in the synthesis of coumarin–chalcone hybrids through the Claisen–Schmidt condensation of different aromatic aldehydes and 3-acetyl coumarin. The nanocomposite increased the rate and facility of the aforementioned reaction and represented a strong influence in the green synthesis of different coumarin–chalcone derivatives. The nanocatalyst has been characterized by N 2 adsorption–desorption, Fourier transform infrared spectroscopy, scanning electronic microscopy, powder X-ray diffraction and energy dispersive spectroscopy. Some advantages of this novel and sustainable approach are high yields of coumarin–chalcone compounds, short reaction times, environmentally benign, recoverability of ZnS NPs/g-C 3 N 4 and reusability without important loss of catalytic activity. Graphical abstract