Dendrimer-encapsulated Pd(0) nanoparticles immobilized on nanosilica as a highly active and recyclable catalyst for the copper- and phosphine-free Sonogashira–Hagihara coupling reactions in water

Abstract

Recyclable dendrimer-encapsulated Pd(0) nanoparticles immobilized on nanosilica in the Sonogashira–Hagihara reaction under copper(i) and phosphine ligand-free conditions in water.

One-pot synthesis of multisubstituted imidazoles catalyzed by Dendrimer-PWAn nanoparticles under solvent-free conditions and ultrasonic irradiation

“…To determine the exact PWA n species responsible for the observed reactions and to measure the extent of tungsten (W) leaching after the reactions, we used the hot filtration test [59]. For this aim, we have studied the model reaction between reaction benzil, benzaldehyde, aniline and ammonium acetate under ultrasonic irradiation in ethanol.…”

Ligand-free Pd(0)/SiO2-catalyzed aminocarbonylation of aryl iodides to amides under atmospheric CO pressure

“…In the case of using N-methyl-m-methylaniline, the yield of 2aq was reduced greatly possibly due to the steric hindrance effect (entry 17). Alkyl and cyclic amines were also reactive, but relatively low yields were obtained (entries [23][24][25] under the current conditions. The recycling of Pd/SiO 2 catalyst was evaluated for the aminocarbonylation of aryl iodides under the optimized reaction conditions.…”

“…3, the peaks around 335.7 eV and 340.8 eV for the fresh Pd/SiO 2 catalyst can be readily assigned to Pd(0) 3d 5/2 and 3d 3/2 bands, in agreement with the literature reports. [25][26][27] Aer the Pd/SiO 2 catalyst was recycled for ve cycles, the two peaks were still located at the same binding energy. Further evidence for Pd was also provided by HRTEM images in Fig.…”

Green, cost‐effective and efficient procedure for Heck and Sonogashira coupling reactions using palladium nanoparticles supported on functionalized Fe3O4@SiO2 by polyvinyl alcohol as a highly active, durable and reusable catalyst

“…One of the most essential reactions in modern synthetic chemistry is carbon–carbon (C–C) coupling reactions . Transition metals or their various complexes have widely been applied as catalysts in many coupling techniques.…”