An Fe₃O₄@Keratin‐Ag(I) Magnetic Nanocatalyst for Facile One‐Pot Sonochemical Synthesis of Isoxazole and Isoxazoline‐1,2,3‐Triazole Hybrids in Water

In this research, we report a one‐pot sequential synthesis of novel hybrid isoxazole or isoxazoline‐1,2,3‐triazole compounds in four steps. The synthetic route involves sulfonylation, 1,3‐dipolar cycloaddition, azidation, and click reaction. The key feature of this methodology is its environmentally friendly approach, which is highlighted by the use of water as a benign solvent and ultrasound activation to increase the efficiency of the heterogeneous reactions. Additionally, a novel magnetic nanocatalyst was prepared by adsorbing silver(I) on keratin extracted from chicken feathers, which both valorizes biomass and strengthens the eco‐friendly nature of the process. The methodology proved its effectiveness by yielding the final products 6a‐i and 7a‐i with remarkable selectivity and high yields (85%–96%) within a significantly reduced reaction time (2.5h). Moreover, the catalyst demonstrated excellent stability, maintaining its performance over five consecutive cycles, confirming its robustness and reusability. The characterization of the nanocomposite catalyst Fe 3 O 4 @KNPs‐Ag(I) and the final products 6a‐i and 7a‐i has been performed using various analytical methods, including FTIR, XRD, SEM‐EDX, ICP‐OES, TEM, HRTEM, TGA, DSC, 1 H NMR, 13 C NMR, 19 F NMR, and HRMS.