Preparation, Characterization and Application of Copper Schiff base Complex Supported on MCM-41 as a Recyclable Catalyst for the Ullmann-type N-arylation Reaction

In this study, a Cu-Schiff base complex supported on highly ordered mesoporous silica MCM-41 was successfully prepared to form a heterogeneous catalyst. The structural and textural properties of the newly prepared catalyst were determined by various microscopic and spectroscopic techniques such as FT-IR, BET, TGA, DRS UV-vis, EDX, XPS, ICP-OES, XRD, and TEM. The catalyst was used in the N-arylation of various amines through formation of intramolecular C(aryl)-N bond from the relevant aryl halides (Ar-I and Ar-Br) with amines by coupling reactions of Ullmann type. The significant advantages of this protocol were generality, low metal content, high yield of products, and simple work-up procedure. Moreover, the catalyst could be recycled efficiently for seven runs without any appreciable decrease in reactivity and no leaching of copper was found during this course.