Sol-gel TiO2 nanostructures single doped with copper and nickel as nanocatalysts for enhanced performance for the Liebeskind-Srogl reaction

Design of nanostructured catalytic materials plays a strategic role in the synthesis of organic compounds with outstanding physicochemical properties. In this regard, titanium dioxide nanostructures doped with a single metal, namely, nickel and copper, were successfully prepared by a sol-gel method, and their phase structures, elemental compositions and morphologies were extensively characterised. In particular, X-ray diffraction (XRD) diffractograms and Raman spectra mainly revealed a rutile-phase structure for Cu-doped TiO2 and a biphasic anatase-rutile structure for Ni-doped TiO2. In addition, catalytic activities of Cu- and Ni-doped titanium dioxide nanostructures were evaluated for the synthesis of pyridopyrimidine derivatives from sulphur intermediates by the Liebeskind-Srogl reaction under UV illumination. Under the optimized reaction conditions, the target compounds were obtained in a yield of up to 87% by using the Cu-doped TiO2 catalyst and with a slightly lower yield of up to 79% for Ni-doped TiO2 in 12 h. Overall, the catalytic activity of Cu-doped TiO2 was greater than that of Ni-doped TiO2.

Automated summary

The catalytic activity of copper-doped titanium dioxide nanostructures was found to be superior to that of nickel-doped titanium dioxide nanostructures in the synthesis of pyridopyrimidine derivatives under UV illumination, with yields reaching up to 87% and 79% respectively within 12 hours.