Copper Nanoparticle-Doped Silica Cuprous Sulfate as a Highly Efficient and Reusable Heterogeneous Catalysis for N-Arylation of Nucleobases and N-Heterocyclic Compounds

A facile and simple protocol for Ullmann-type N-arylation of nucleobases with aryl halides is described using copper nanoparticle-doped silica cuprous sulfate (CN-DSCS) as a new and efficient heterogeneous catalysis. In this method, treatment of various nucleobases and aryl halides in the presence of DBU and CN-DSCS in refluxing DMF furnishes the corresponding N-aryl adducts in reasonable to good yields. The CN-DSCS was fully characterized by different microscopic, spectroscopic and physical techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), inductively coupled plasma (ICP) analysis, thermogravimetric analysis (TGA), and FT-IR. The CN-DSCS was proved to be a chemically and thermally stable, cheap, and environmentally compatible heterogeneous nanocatalyst that can be reused for many consecutive experiments without any considerable decrease in its reactivity.