Synthesis of dendrimers terminated by DABCO ligands and applications of its palladium nanoparticles for catalyzing Suzuki–Miyaura and Mizoroki–Heck couplings

A new kind of silica‐supported third‐generation dendrimers capped by 1,4‐diaza‐bicyclo[2.2.2]octane (DABCO) group‐stabilized palladium(0) nanoparticles, and their enhanced catalytic activity in Suzuki–Miyaura and Mizoroki–Heck reactions in excellent yield under mild conditions, was reported. The resulting silica‐supported dendrimer‐stabilized palladium(0) nanoparticles with a particle size of 10–20 nm were prepared in situ by treatment with PdCl 2 and hydrazine in ethanol at 60 °C for 24 h. The catalyst as prepared was characterized by FT‐IR, X‐ray diffraction, thermal analysis, elementary analysis (EA), scanning electron microscopy and transmission electron microscopy . Recycling experiments showed that the catalyst could be easily recovered by simple filtration and reused for up to five cycles without losing its activity. Copyright © 2012 John Wiley & Sons, Ltd.