Preparation and Characterization of Ionic Liquid Supported on Fe3O4-Lignin and Investigation of Its Catalytic Activity in the Synthesis of Dihydropyrano[3,2-c] chromene Derivatives

To extend the use of supported ionic liquids as effective heterogeneous catalysts, in this research, the ionic liquid immobilized on magnetic lignin (Fe3O4-lignin-SO3/IL) was used as an environmentally friendly, and recyclable catalyst for the synthesis of dihydropyrano[3,2-c]chromene derivatives via a one-pot reaction between aromatic aldehydes, malononitrile, and 4-hydroxycoumarin. This method offers the benefits of high yield, short reaction times, straightforward processing, and its potential for green applications in pharmaceutical and chemical sectors. Furthermore, the detailed role of Fe3O4-lignin-SO3/IL as a catalyst in chemical reactions was examined, providing insights into its mechanism and potential uses in organic synthesis and other chemical processes.