In this thesis, An interesting silica-supported nano-palladium catalyst was successfully prepared through ‘‘click’’ reaction of azide-functionalized silica with methylpropargylimidazolium bromide followed by immobilization of palladium nanoparticles (NPs), in which the click-triazole as an important functional entity acts as both a stable linker and a good chelator. The as-prepared nanocatalyst was well characterized and found to be highly efficient in Heck and Suzuki–Miyaura coupling in terms of activity and recyclability in aqueous ethanol under phosphine-free and low Pd loading (0.1 mol%) conditions. In the next section, we have applied nickel nanoparticles supported on modified multiwalled carbon nanotubes as highly selective, economical and efficient heterogeneous catalysts in the Suzuki cross-coupling reaction. The corresponding Suzuki products were obtained in good yields under relatively mild reaction conditions. In the next step, we have reported the preparation of new functionalized chitosan with an alkynlated imino- thiophene ligand via a “click” route. The newly designed material has been applied as an economical and effective support for heterogeneous nickel nanoparticle which was efficiently used as catalysts for Suzuki cross-coupling reactions. Additionally, high catalytic activity, broad substrate scope, reusability and the use of an inexpensive chitosan and nickel make it a desirable protocol from environmental and industrial view point. Finally, we have established an efficient strategy to modification of M surface with azide group via the ring opening of oxiran groups and its further functionalization using click reaction for the immobilization of Ni nanoparticles. The newly designed material was used as an economical and practical heterogeneous organocatalyst for the Hiyama cross-coupling reaction under fluoride-free conditions. Furthermore, the high catalytic activity, ease of recovery, reusability and the use of an inexpensive nickel metal makes the reported protocol valuable from industrial and environmental viewpoint. Moreover this is the first report based on the design of Ni-containing magnetically separable organocatalyst for performing Hiyama cross-coupling reaction between a variety of aryl halides and triethoxyphenylsilane.
