A Green and Efficient Approach for Preparation of Diaryl Sulfones: Fe3O4@DABA-PA-CuBr2 Nanocomposite Catalyzed One-Pot Three-Component Aryl Iodides, Aryl Boronic Acids, and DABSO (as SO2 Source)

Abstract
In this research work, Fe3O4@DABA-PA-CuBr2 nanocomposite was fabricated by a simple and inexpensive method by immobilizing copper(II) bromide on the surface of magnetic nanoparticles modified with 3,4-diaminobenzoic acid and picolinic acid. Deep eutectic solvents or DESs are green and environmentally friendly solvents that are used as catalyst or solvent in many reactions. The utilization of Fe3O4@DABA-PA-CuBr2 nanocatalyst in ChCl-Urea at 100 degrees C presented an attractive, environmentally benign and highly efficient catalytic system for the preparation of a broad range of diaryl sulfones through one-pot three-component coupling of aryl iodides, aryl boronic acids, and DABSO (as SO2 source). It should be noted that the Fe3O4@DABA-PA-CuBr2 catalyst was used several times without significant reduction of the catalytic activity. VSM, TEM, and ICP-OES analysis of the reused Fe3O4@DABA-PA-CuBr2 catalyst after eight cycles revealed that that the structure, magnetic property, shape, and size of the particles did not change significantly.