A nanomagnetic triazole-based Schiff-base complex of palladium(0) as an efficient heterogeneous catalyst for the Mizoroki–Heck C–C cross-coupling reaction under green conditions

Abstract

A novel magnetically recoverable palladium(0) catalyst, [Fe₃O₄@triazole-Schiff-base-Pd(0)], was synthesized via a simple three-step functionalization. Magnetite nanoparticles were first modified with a haloalkane silane linker to introduce C–Cl functionalities, followed by nucleophilic substitution with a triazole-Schiff-base ligand derived from 3-amino-1,2,4-triazole and salicylaldehyde. Finally, coordination with palladium chloride and in situ reduction to Pd(0) afforded a stable, magnetically separable catalyst. Comprehensive characterization (FT-IR, XRD, TGA, EDX, ICP-OES, WDX, FE-SEM, TEM, and VSM) confirmed its successful synthesis. The catalyst demonstrated outstanding activity in the Mizoroki–Heck C–C cross-coupling reaction, resulting in efficient coupling of a diverse range of aryl iodides, bromides, and chlorides with butyl acrylate in PEG-400 as a green solvent and co-catalyst. It exhibited superior selectivity for aryl iodides and bromides and maintained high efficiency over eight consecutive cycles with minimal metal leaching. The use of cost-effective materials, facile magnetic recovery, and scalability make this catalyst an eco-friendly and economically viable alternative to conventional palladium-based methodologies.