A magnetic catalytic substrate based on Fe/Pd nanoparticles and vanillin-functionalized κ-carrageenan for quick Suzuki–Miyaura coupling reactions

Abstract

A novel magnetic nanocatalyst was prepared by functionalization of κ-carrageenan (Car) natural polymer with vanillin linker (Van) and then immobilization of palladium nanoparticles (Pd NPs) on it utilizing a facile approach. The analytical characterization of the prepared Fe3O4@Car/Van-Pd catalyst was carried out through appropriate analyses. Applying the prepared Pd-containing nanocomposites in Suzuki − Miyaura cross-coupling reactions exhibited privileges, such as enhanced thermal stability up to 450 °C, low toxicity, and insensitiveness to moisture and oxygen. However, this nanocatalyst presented many remarkable characteristics, such as excellent dispersion of spherical Pd NPs on the Fe3O4@Car/Van support and short-time catalysis of the biphenyl derivatives with exceptional yields. The prepared nanocatalyst exhibited 97.0 ± 0.32% Suzuki − Miyaura cross-coupling reaction yield after 12 min at ambient temperature and pH of 9.0 by applying only 0.01 g of the catalyst. The heterogeneous Fe3O4@Car/Van-Pd magnetic nanocomposite with superparamagnetic behavior (Ms = 30.9 emu g−1) was collected using an external magnet with convenience. Besides, the catalytic activity of this magnetic nanocatalyst was preserved even after ten reaction cycles without any considerable catalytic performance decrease. Moreover, applying a natural polymeric substrate, the cost-effectiveness, the raw materials availability, good thermal stability, convenient magnetic recovery, simplicity in operation, and high reaction yields are beneficial parameters that make the Fe3O4@Car/Van-Pd heterogeneous catalyst superior to other catalysts.