Silk Fibroin Functionalized with CuSO4 on Knoevenagel Condensation Under Microwave Radiation

Background: The advantages of microwave (MW)-assisted chemistry reactions have led several research groups to apply this technique to the optimization of synthetic processes and the preparation of new compounds. This research focuses on Knoevenagel condensation with additives supported on natural fibers (Fibroin and Kapok) under MW. Methods: Under these experimental conditions, 2-benzylidenemalononitrile was synthesized at 60°C under MW radiation of 10 min using acid and base additives like soluble imidazole and CuSO4, solid silica, and inert fibers (e.g., Fibroin and Kapok). Results: The reactions afforded good yield for 2-benzylidenemalononitrile using the fibroin functionalized. Fibroin-CuSO4 can be reused at least three times and synthesizes several 2-arylidenemalononitrile derivatives (71-77 % at 60°C for 10 min) under MW used MeOH as solvent. Conclusion: This study investigated the use of fibroin functionalized with CuSO4 on Knoevenagel condensation under microwave radiation to synthesize 2-benzylidenemalononitriles in eco-friendly conditions.