Eco-friendly magnetic nanocatalysts: Optimized pyrrole synthesis via ternary Fe x Cu y M z O k (M = Zn, Mn) nanocomposites

Ternary magnetic nanocomposites of the compositions FexCuyZnzOk and FexCuyMnzOk were prepared through a simple, cost-effective, linker-free strategy, and characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and vibrating sample magnetometry. These nanocomposites showed excellent catalytic performance in the multicomponent synthesis of pyrrole derivatives from aromatic aldehydes, anilines, and ethyl pyruvate. Under mild reaction conditions, FexCuyZnzOk provided the target N-heterocyclic products in 78–93% isolated yields at room temperature within 2 h. The catalyst displayed crystallite sizes of 50.2 nm and saturation magnetization values of 50–60 emu g−1, and could be reused for five consecutive cycles with more than 90% retention of its catalytic activity. The observed performance is attributed to synergistic interactions among the metal oxide constituents, which enhance both catalytic efficiency and structural stability. Overall, this work introduces a magnetically recoverable heterogeneous catalyst for the efficient synthesis of pyrrole derivatives.