Heterogenization of Cobalt on Nanostructured Magnetic Covalent Triazine Framework: Effective Catalyst for Buchwald-Hartwig N-Arylation, Reduction, and Oxidation Reactions

Abstract

The present study describes a methodology to heterogenize metallic Co nanoparticles (NPs) on hollow Fe 3 O 4 nanospheres, surfacefunctionalized with a porous covalent triazine framework, leading to a magnetically separable catalyst that exhibits efficient catalytic activity in hydrogenation, ligand-free Buchwald-Hartwig N-arylation, and oxidation reactions. Here, the presence of a nitrogen-enriched porous structure is expected to provide potential interactions with active centers through coordination (M←N), enable the isolation of the entrapped catalytically active Co NPs, and prevent the possibility of sintering during catalytic reactions, resulting in structurally stable catalytic sites, which makes them recyclable without any loss in activity.

Construction of a Dual-Functionalized Acid–Base Nanocatalyst via HEPES Buffer Functionalized on Fe3O4 as a Reusable Catalyst for Annulation Reactions

“…The immobilization of catalytic moieties on the surface of materials such as boehmite, silicates, polymers, − metal–organic frameworks, − and magnetic spinel ferrite particles can overcome challenges in their reusability and separation from reaction mixtures. This hybrid material catalysis harnesses the synergistic properties of diverse components to drive efficient and selective chemical transformations. ,− Significantly, magnetic NPs (MNPs) exhibit considerable potential in organic synthesis as a heterogeneous catalyst, primarily owing to their convenient separability and ability to be reused. − Immobilizing catalytic agent components on magnetic nanomaterials with a large surface area enhances their catalytic performance. , Magnetite iron ferrite NPs find extensive application in diverse organic synthesis procedures owing to their exceptional surface characteristics. − However, a direct connection of iron oxide to HEPES through hydrogen bonding is not easily achievable. To address this constraint, utilizing an effective linker between Fe 3 O 4 and HEPES can enhance the activities of the target chemosorbed catalyst via preventing physical absorption that can lead to agglomeration of the catalyst structure.…”