Magnetic Coconut Shell‐Derived Activated Carbon Adorned with Cu2O Nanoparticles: A Green and Efficient Porous Catalyst for N‐Arylation of Hetero‐Aromatics in Eutectic Medium

Abstract

AbstractIn the current research, a green, robust, and economical metal oxide‐based nanocatalyst has been developed by functionalization of coconut shell‐derived mesoporous activated carbon with magnetically separable amino acid and subsequent decoration with Cu2O nanoparticles (Fe3O4@L‐arginine‐AC−Cu2O). This magnetic nanostructure was analyzed by different techniques including FT‐IR, FE‐SEM, EDX/MAP, XRD, TEM, TGA, VSM, BET, and ICP‐OES. The catalytic efficiency of the nanoparticles was studied in Ullmann N‐arylation reaction of some N‐heterocycle compounds including indole, imidazole, and pyrrole with various aryl halides in choline chloride/glycerol (1 : 2), which is a green and biomass‐based deep eutectic solvent (DES). The reaction proceeded smoothly and the desired N‐arylation products were obtained in good to excellent yields (75‐96 %). Notably, the magnetic porous nanocatalyst can be easily separated and reused at least six times without a notable decrease in its performance. The solvent is also able to recover, thereby increasing the attractiveness of this approach. In other words, this approach can serve to significantly expand the scope of the C−N coupling products for their applications in further studies.