Dmitry Tsvelikhovsky - Three Phase Microemulsion/Sol–Gel System for Aqueous C–C Coupling of Hydrophobic Substrates

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      Publication Details (including relevant citation   information):

      Dmitry Tsvelikhovsky[a] and Jochanan Blum*[a]

     

      Eur. J. Org. Chem. 2008, 2417–2422

     

      Institute of Chemistry, Hebrew University, Jerusalem 91904,   Israel Fax: +972-2-6513832 jblum@chem.ch.huji.ac.il

     

      Abstract:

      Heck, Stille, Suzuki and three-component coupling reactions with   hydrophobic substrates have been carried out in water. The   substrates are initially transformed by a general pro- cedure   into a microemulsion, which consists of nearly 90% water with the   aid of sodium dodecyl sulfate and either PrOH or BuOH. The   surfactant carries the molecules of the sub- strates to Pd(OAc)2   entrapped within a hydrophobicitized sil- ica sol–gel matrix   where the coupling between the substrates is assumed to take   place. The products are then returned by the surfactant into the   microemulsion from which it can be released. The immobilized   palladium catalyst is leach proof and recyclable. It can be used   in various coupling processes at least six times without loss of   activity. Experiments with D2O have revealed that the water does   not take part in the coupling process, but it has an effect on   the pore size of the sol–gel matrix, which hosts the palladium   catalyst.

     

      Address (URL): http://onlinelibrary.wiley.com.libproxy.mit.edu/doi/10.1002/ejoc.200800028/pdf