Catalysis Letters, Vol.143, No.4, 317-323, 2013
The Effect of PEGylated Dendrimers on the Catalytic Activity and Stability of Palladium Particles in the Suzuki Reaction
Stable dendrimer-coated Pd particles were synthesized using the wet-chemical borohydride reduction method of Pd(II) salts in the presence of low-generation (poly)ethylene glycol-terminated amidoamine-based dendrimers. The identity and structure of the Pd-containing colloids were analyzed by FT-IR spectroscopy, X-ray powder diffraction, thermogravimetric analysis, atom absorption spectroscopy and UV-Vis spectroscopy. Dynamic light scattering experiments have been performed to determine the hydrodynamic diameter of the particles (350-900 nm). The performance of the thus obtained dendrimer-stabilized Pd particles in Suzuki C,C cross-coupling reactions of aryl halides and phenyl boronic acid was examined. Turn over numbers of up to 930 could be achieved. The influence of the dendritic stabilizers on the particle size along with the catalytic performance is presented.