Fabrication, characterization and application of magnetic chitosan supported copper(II) complex as an effective catalyst for N-arylation of sulfonamides with arylboronic acids

Chitosan (CS) comes from the deacetylation of chitin, which is a hydrophobic polysaccharide made from acetyl-glucosamine and glucosamine grafts and found in the outer skeleton of shellfish, shrimp, squid, lobsters and crabs or walls of algae, etc. [1]. Therefore, chitosan is environmentally benign, biodegradable, non-toxic and available. Because of these properties, chitosan can be used as an important support for catalytic systems [2].Sulfonamides are known as important synthetic compounds, which have been widely used as antibacterial materials. N-Arylation of sulfonamides with arylboronic acids can be catalyzed using a biopolymer supported metal complex [3].In the present work, the organic copper complex (metformin (Met) copper(II) complex) was immobilized on the magnetic chitosan using (3-chloropropyl)trimethoxysilane. The [Fe3O4/CS-Met-Cu(II)] as a new, effective and reusable catalyst was fully characterized by using various techniques such as FT-IR, XRD, FE-SEM, HRTEM, EDS, VSM, and TG-DTA. The synthesized heterogeneous catalyst has high catalytic performance for the N-arylation of sulfonamides with arylboronic acids in ethanol. This method has many advantages such as high yields, using heterogeneous catalysts instead of homogeneous ones, green reaction conditions, and simple procedure. The catalyst could be recycled and reused for several cycles without significant loss of activity.

Keywords:

Magnetic chitosan , N-Arylation , Sulfonamides , Fe3O4/CS-Met-Cu(II)