Magnetic Cellulose Nanofibers Supported Imidazolium-Based IonicLiquid as a Biodegradable Catalyst for the Synthesis of Quinoline Derivatives

Ionic liquids are a class of liquids that are composed solely of ions. They are non-volatile,non-flammable, thermally stable, and have excellent solvation properties, thus find potentialapplications in catalysis, electrochemistry. Supported ionic liquid catalysis is a concept whichcombines the advantages of ionic liquids with those of heterogeneous support materials [1].As an excellent support, cellulose is of great interest due to its good biocompatibility, biodegradationand non-toxicity. Furthermore, the cellulose nanofibers (CNF) has a large surfacearea, many available functional groups and high mechanical strength, which makes it an attractivecandidate as a supporting material for the synthesis of heterogeneous catalysis. Onother hand, as the recovery of the most heterogeneous catalysts from the final reaction systemsrequires filtration or centrifugation step as a time consuming and tedious process, forthis reason, they have been coated with magnetic nanoparticles. Magnetically recoverable catalystscan be easily separated with an external magnetic field [2]. Because of quinoline importanceas substructures in a wide range of natural and semisynthetic products, significantefforts are directed to the development and construction of new quinoline-based structures[3]. In this study we report the synthesis of imidazolium-based ionic liquid immobilizated onmagnetic cellulose nanofibers (Fe3O4@NFC-IIL-HSO4) and its identification by various techniqueslike FTIR, TGA, SEM, TEM, ICP-AES and VSM. The applicability of the constructedheterogeneous nanocatalyst was explored in the synthesis of quinoline derivatives throughreaction of 2-Aminobenzophenones with ketones and diketones at 90 °C under solvent-freeconditions in excellent yields.