Applicability of Magnetically Recyclable Ferrite-L-Cysteine Nanocatalyst for the Green Synthesis of Quinoline and Pyrazole Derivatives Under Microwave Irradiation

Background: Recently sustainable transformations are a challenge for the researchers in areas like health, social sector and environment. To overcome these troubles, it has been planned to produce simple and facile methods to carry organic reaction under mild & eco-friendly conditions. Nano magnetite supported catalysis is a very significant and growing field in catalytic science with application in organic synthesis. Therefore, this research article focuses on the synthesis of nano-magnetite supported cysteine organocatalyst and its application in catalysis and synthetic organic chemistry. Methods: Magnetically recyclable heterogeneous catalyst ferrite-L-cysteine was prepared by simple stirring method in distilled water media without any other reagent followed by dehydration technique. The synthesized catalyst is well characterized by FT-IR, TEM and FEG-SEM-EDS spectroscopy. This functionalised nanocat- Fe-cys was employed in the synthesis of quinolines under Friedlander reaction and also pyrazole derivative under Knoevenagel condensation reaction. The % conversion of products was checked by thin layer chromatography and the synthesized compounds were further confirmed by NMR techniques. Results: To check the competency of synthesized nanocat-Fe-cys for Friedlander & Knoevenagel raction under solvent free conditions, microwave irradiation method employed superiorly over conventional oil bath method. The products were obtained in very clean & noticeably higher yield (81-94%). The catalyst ferrite cysteine was found to be recyclable for ten consecutive run with no significant loss in catalytic activity. Conclusion: In the present research article, the synthesis of highly active, recyclable & versatile organo nanocatlyst ferrite-cysteine using easily available precursor via the simple impregnation procedure is presented. The MNPs was found to be stable under investigated conditions & highly effective in the synthesis of substituted quinolines and pyrazole derivatives. The simple eco-friendly method, mild reaction conditions, economically affordable and good product yields make it an attractive sustainable protocol.