Tetramethyl-dipropylene-triamine-modified triazine immobilized on silica-coated magnetic nanoparticles: an eco-friendly and reusable catalyst for the solvent-free synthesis of 2-amino-4H-chromene derivatives

In this study, an eco-friendly and reusable nanocatalyst was developed by modifying silica-coated magnetic nanoparticles (MNPs) with tetramethyldipropylenetriamine (TM-DPT) and 2,4,6-trichloro-1,3,5-triazine (TCT). The resulting material was characterized using various techniques, including FT-IR, XRD, EDX, FESEM, VSM, and TGA analysis, confirming its successful synthesis and structural integrity. The results indicate that the innovative nanocatalyst, labeled MNPs@TCT/TM-DPT, exhibits uniform size distribution, minimal aggregation, and excellent thermal stability up to 200 °C, while maintaining an intact Fe₃O₄ core and a stable surface coating. The catalytic performance of the nanocatalyst was evaluated in the solvent-free synthesis of 2-amino-4H-chromene derivatives, which are important heterocyclic compounds. The synthesis involved a one-pot reaction of aromatic aldehydes, malononitrile, and enolizable C–H acids under mild conditions, achieving high yields efficiently. In alignment with green chemistry principles, the nanocatalyst demonstrated excellent recoverability using an external magnet, retaining its catalytic activity over six consecutive cycles. Comparative analyses highlighted its high-yield synthesis, eco-friendly conditions, and robust reusability, establishing it as a sustainable and effective catalyst for organic synthesis.

Graphical abstract