Magnetic nanoparticles β-Cyclodextrin-supported nickel catalyst (Ni-MNPCD): Efficient, sustainable and reusable...

In this work, a new nickel-based catalyst, nickel supported on β-cyclodextrin-functionalized magnetic nanoparticles (Ni-MNPCD), was developed for sustainable and ligand-free Heck carbon-carbon (CC) and Buchwald-Hartwig carbon-nitrogen (CN) cross-coupling reactions. The Ni-MNPCD catalyst benefits from the incorporation of β-cyclodextrin (β-CD), which acts as a biocompatible support to stabilize nickel, enhance metal dispersion, and facilitate ligand-free operation. The Ni-MNPCD catalyst was fully characterized using various techniques, including FT-IR, XRD, FE-SEM, EDX-Mapping, ICP, TEM, XPS, TGA, and VSM, which confirmed its successful synthesis, stability, and microscopic and macroscopic structure. By utilizing phenols instead of traditional aryl compounds, the approach significantly reduces material costs and environmental impact, while also improving raw material availability. The activation of phenols is efficiently achieved using 2,4,6-Trichloro-1,3,5-triazine (TCT), which provides a simpler and more efficient activation process compared with the conventional methods. The Ni-MNPCD catalyst operates under mild reaction conditions and achieves high yields in both CC and CN bond formations. The recyclability of the catalyst, systematically evaluated here, together with the elimination of expensive ligands and precious metals, supports the sustainability and practicality of the protocol. Additionally, the catalyst exhibits a broad substrate scope, enabling coupling reactions with various amines and vinyl compounds, thereby highlighting its wide applicability in organic synthesis.