Using the Vapourtec R-Series flow chemistry system researchers from the Centre for Sustainable Chemical Technologies at the University of Bath have shown the development, preparation and use of two novel polymer encapsulated silica supported palladium catalysts for cross coupling reactions which were shown to be highly reactive, robust of reusable. The catalysts were also demonstrated with over 50 hours of continuous operation with no decrease in activity and low levels of leaching.
Palladium catalysed cross-coupling reactions are a key tool for synthetic chemists due to their functional group tolerance and versatility. They allow access to a large number of coupled aryl, heteroaryl and alkyl structures which has led recently to an increasing amount of interest in performing reactions of this type under continuous flow conditions.
There have been a number of publications using supported palladium catalysts with varying amounts of leaching reported. Minimising palladium content is a particular problem in the pharmaceutical industry where leaching of the catalyst, loss of activity and subsequent removal of palladium residues is unwanted and can be expensive.
The group from Bath have shown two highly active, robust and reusable polymer encapsulated Pdo catalysts for Suzuki-Miyaura and Heck cross-coupling reaction in high conversions and short residence times. The catalysts were demonstrated with over 50 hours of continuous use with levels of Pd leaching at 1ppm (0.05%) and no reduction in activity.Find out more Published papers
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