CuO−La2O3 Nanocomposite as a Recyclable and Eco-Friendly, Heterogeneous Catalyst for the One-Pot Synthesis of Pyrano [2, 3-c] Pyrazoles

Abstract

In this work, the unique performance of binary acid-base CuO/La2O3 nanocomposite as a highly efficient heterogeneous catalyst was successfully examined for the one-pot multicomponent synthesis of pyrano [2, 3-c] pyrazole derivatives. The strong interactions between La and Cu had a profound effect on the catalytic activity of nanocatalysts. In addition, high selectivity, easy recovery, reusability, a very reasonable price, simple preparation and eco-friendliness are other important advantages of this nanocatalyst. The characterized nanocomposite demonstrated excellent structural and morphological properties, leading to high catalytic efficiency. Characterization using Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Powder Diffraction (XRD) confirmed crystallographic structure, and Field Emission Scanning Electron Microscopy (FE-SEM) showed a spherical particle size of approximately 43 nm. Energy-Dispersive X-ray (EDX) analysis confirmed the composition of La, O, and Cu elements in the nanocomposite as 86.4 %, 13.5 %, and 0.2 %, respectively. The optimal condition for the synthesis resulted in a 98 % yield of pyrano [2, 3-c] pyrazole derivatives under reflux with 0.02 g of CuO/La2O3 catalyst in a 10-minute reaction time.