학술논문

Magnetically recoverable catalysts based on mono- or bis-(NHC) complexes of palladium for the Suzuki–Miyaura reaction in aqueous media: two NHC–Pd linkages are better than one.
Document Type
Article
Source
Dalton Transactions: An International Journal of Inorganic Chemistry. 8/7/2016, Vol. 45 Issue 29, p11633-11638. 6p.
Subject
*PALLADIUM catalysts
*PALLADIUM compounds
*SUZUKI reaction
*SILICA
*MAGNETIC separation
*MAGNETIC nanoparticles
CATALYSTS recycling
Language
ISSN
1477-9226
Abstract
Pre-synthesized mono- and bis(NHC) palladium complexes have been grafted onto magnetic core/shell γ-Fe2O3/silica particles and tested as catalysts in model Suzuki–Miyaura coupling reactions. The bis(NHC) immobilized complex was found to be a robust catalyst that can operate under mild conditions in aqueous media, even for the activation of chloroarene, whereas the mono(NHC) counterpart rapidly deactivates. Moreover, it can be readily recovered by magnetic separation and reused many times, providing very high productivities, and with so low leaching of palladium that the crude products obtained contain ≤10 ppm Pd. [ABSTRACT FROM AUTHOR]