Fabrication of Core–Shell-Structured Organic–Inorganic Hybrid Nanocatalyst for the Expedient Synthesis of Polysubstituted Oxazoles via Tandem Oxidative Cyclization Pathway

[Image: see text] The quest for designing efficient heterogeneous catalytic systems for tandem oxidative cyclization reactions has provided a great impetus to research efforts, as it enables the step-economic construction of complex heterocyclic molecules as well as confers the benefits of a facile catalytic recovery. In the present study, we disclose a new core–shell-structured organic–inorganic hybrid copper nanocatalyst fabricated via the covalent grafting of 2,2′-dipyridyl ketone ligand on amine-functionalized silica-encapsulated magnetite nanoparticles, followed by its metallation with cupric acetate for the tandem oxidative cyclization of amines and β-ketoesters, leading to the production of biologically active polysubstituted oxazole moieties. This programmed catalytic protocol proceeds via the formation of intermolecular C–C and C–N bonds by single-step synthesis and accommodates a broad combination of reaction coupling partners.