Imidazolium based Ionic liquid Anchored over Dendritic Mesoporous Silica Nanospheres possessing a Magnetic Core as an Efficient and Recyclable Base Catalyst

Abstract In this study, Magnetic core‐shell dendritic mesoporous silica nanospheres immobilized with imidazolium‐based di‐cationic ionic liquid (Fe 3 O 4 @SiO 2 @DSiO 2 ‐Im‐IL) possessing a large surface area and numerous active site for adsorption of various molecules to carry out organic transformations have been successfully developed. The synthesized nanocatalyst was found to be easily recyclable by applying external magnetic force. The structure, morphology, thermal stability, and magnetic behavior of the synthesized magnetic nanocatalyst were confirmed by different physiochemical techniques like FT‐IR, P‐XRD, FE‐SEM, TGA, VSM, BET, and TEM analysis. The efficiency of the developed heterogeneous nanocatalyst has been investigated for the green synthesis of numerous benzopyran derivatives by employing different aldehydes and active methylene compounds. The catalyst exhibits marvellous activity and efficiency in terms of high product yield, less catalyst use, and wide substrate scope even at room temperature. Finally, after the successful formation of the product, the catalyst was regenerated by utilizing an external magnetic field. The catalyst has been reused multiple times without any noteworthy loss in its activity which confirms the stability of the developed catalyst. The preparation of the catalyst is cost‐effective, and shows atom economy with the utilization of green solvent and without any waste production, which authenticates that it could be a greener pathway for the synthesis of the benzopyran derivatives.