Synlett 2008(10): 1547-1552  
DOI: 10.1055/s-2008-1078430
CLUSTER
© Georg Thieme Verlag Stuttgart · New York

Efficient and Recyclable Catalyst of Palladium Nanoparticles Stabilized by Polymer Micelles Soluble in Water for Suzuki-Miyaura Reaction, Ostwald Ripening Process with Palladium Nanoparticles

Irina P. Beletskaya*a, Alexander N. Kashina, Irina A. Khotinab, Alexey R. Khokhlovc
a Department of Chemistry, Moscow State University, Leninskie Gory, 119992, Moscow, Russian Federation
Fax: +7(495)9393618; e-Mail: beletska@org.chem.msu.ru;
b A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Science, Vavilova str. 28, 119991, Moscow, Russian Federation
c Department of Physics, Moscow State University, Leninskie Gory, 119992, Moscow, Russian Federation
Further Information

Publication History

Received 16 January 2008
Publication Date:
19 May 2008 (online)

Abstract

The Suzuki-Miyaura cross-coupling reaction of ArX (I, Br) with Ar′B(OH)2, catalyzed by Pd-containing water-soluble micelle formed by PS-PEO copolymer and N-cetylpyridinium chloride as a surfactant, was studied in water and methanol. The reaction was performed under mild conditions (temperature up to 50 °C) and the catalyst can be recycled (5 runs) by ultrafiltration without any loss of its catalytic activity. The phenomenon was observed, consisting in growing Pd-nanoparticle size because the small nanoparticles dissolve to form larger nanoparticles in the course of reaction as well as in the presence of the only reagent, ArI. In the latter case, additionally, the formation of very small, not completely dissolved Pd nanoparticles, obviously having a high catalyst activity, is observed. This observation, together with the catalyst activity data might have an implication for a leaching mechanism for the studied catalytic system.

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In water, these compounds precipitate the catalyst, making it looking like black oil, probably because of the interaction with the hydrophobic part of the micelle.

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The catalyst ultrafiltration was performed with equipment XFUF 04701 Millipore Ultrafiltration Stirred Cell, 47 mm; the membrane of regenerated cellulose with NMWL 3,000.