Polymer-coated palladium nanoparticle catalysts for Suzuki coupling reactions.
J Colloid Interface Sci
; 439: 154-61, 2015 Feb 01.
Article
em En
| MEDLINE
| ID: mdl-25463188
ABSTRACT
A set of seven different palladium nanoparticle (PdNP) systems stabilized by small amounts (1.0mg/mL) of structurally related macromolecular capping agents were comparatively tested as catalyst in p-nitrophenol (Nip) reduction and Suzuki cross-coupling reactions. The observed rate constants (kobs) for Nip reduction were in the range of 0.052-3.120×10(-2)s(-1), and the variation reflected the effects of polymer chain conformation, ionic strength and palladium-polymer complex coordination. Macromolecules featuring pendant pyridyl moieties or inverse temperature-dependent solubility were found to be unsuitable capping agents for PdNPs catalysts, despite being active. The catalytic activity in Suzuki cross-coupling reactions followed the same behavior; the most active particles in the Nip reaction also mediated the cross-coupling reaction providing the expected products in quantitative yields under relatively mild conditions after only 4h at 50°C. Experiments involving the successive addition of reactants and catalyst recovery/re-use indicated that the recycling potential was comparable to those of the standards used in this field.
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MEDLINE
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En
Ano de publicação:
2015
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Article