nickel nps @n-doped titania: an efficient and recyclable heterogeneous nanocatalytic system for one-pot synthesis of pyrano[2,3-d]pyrimidines and 1,8-dioxo-octahydroxanthenes

Catalysis holds a very important and promising place in chemical industry. in a typical chemical transformation, the use of a catalyst reduces the reagent-based waste and enhances the reaction selectivity, thereby minimizing the chances of getting any side product. in the recent years, the introduction of nanotechnology in the field of catalysis has further revolutionized it. it is the extremely small size, shape and remarkably large surface-area-to-volume ratio which sets apart a nanocatalyst from its ordinary bulk form and imparts it unique catalytic properties. in the present work, we report the application of heterogeneous nickel nanoparticles in the synthesis of some biologically important heterocyclic compounds. in brief, we doped titania nanostructures with nitrogen and then used them as a support material for immobilizing nickel nanoparticles onto them. the nanoparticles of nickel were prepared by the chemical reduction of nickel acetate. the catalyst thus prepared, i.e., nickel nanoparticles loaded over nitrogen-doped titania (nickel nps @n-doped tio2), was then explored for its catalytic activity toward the synthesis of pyrano[2,3-d]pyrimidines and 1,8-dioxo-octahydroxanthenes. the surface and the elemental composition of the catalyst was studied by sem–edx analysis. tem analysis was done to study the internal morphology and the size of the nanostructures formed. the other studies included tga, ftir and xps which gave information regarding thermal stability, presence of nitrogen in the titania framework and oxidation state of the nickel nanoparticles, respectively.