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Evaluation of resin plugs as supports for palladium catalysts and peptide synthesis

Resin plugs were developed back in 1999 as a convenient form of resin handling. In this modular cylindrical format, resin beads are embedded in an inert, porous polymer matrix. In this study, the physical and chemical characteristics of resin plugs were evaluated under a variety of reaction conditions, looking at their physical integrity, their chemical utility and reaction uniformity throughout the plugs. Investigations using Raman microscopy showed uniform beads distribution. Plugs were subjected to microwave chemistry and it was demonstrated that temperatures had to be carefully controlled to maintain their physical shape. A number of plugs-supported Pd catalysts were prepared: phosphine ligand-bound Pd, anchored palladacycle and cross-linked resin plugs-entrapped Pd. Their activity was assessed in Suzuki, Sonogashira and Heck cross-couplings and ranged from moderate to excellent. The latter displayed the best properties (activity, recyclability, low leaching), while reaction times could be reduced from days to minutes through the use of microwave irradiation. 3-phase tests revealed that the catalysts were truly heterogeneous when supported on the m-XL-Pd plugs. Peptides were synthesised on plugs with great efficiency and purity by either continuous flow or use of microwave irradiation.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:659859
Date January 2007
CreatorsNajman, Romain
PublisherUniversity of Edinburgh
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Sourcehttp://hdl.handle.net/1842/15482

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