Immobilized β-cyclodextrin and palladium-pyridylaldehyde complex on silica nanoparticles as a highly active catalyst for Suzuki, reduction of nitroarenes and oxidative amination of aldehydes reactions in water

Abstract A novel high-efficiency nanocatalyst (SiO2@β-CD@Pd-PDR) was prepared, which was designed with SiO2 as the core, water-soluble β-cyclodextrin as the shell, and palladium-pyridylaldehyde complex (Pd-PDR) as the catalytic center inserted into the two layers. The catalyst was characterized extensively by FTIR, XRD, TEM, EDS, NMR, AAS, XPS and XRF, and it was found to be completely water-soluble upon heating. Herein, the versatility of the catalyst was evaluated in three different types of reactions Suzuki coupling, nitroarene reduction, and oxidative amination of aldehydes in water and yielded high TON values (up to 2200). Most importantly, the catalyst was recovered and recycled ten times without significant decrease in catalytic activity. Furthermore, there was no leaching of Pd into solution (ICP-OES) during the reaction. Therefore, this catalyst is an environment-friendly alternative that can be utilized for green organic synthesis.