Synthesis 2008(10): 1589-1599  
DOI: 10.1055/s-2008-1072579
PAPER
© Georg Thieme Verlag Stuttgart · New York

Carbon-Carbon Cross-Coupling Reactions under Continuous Flow Conditions Using Poly(vinylpyridine) Doped with Palladium

Klaas Mennecke, Wladimir Solodenko, Andreas Kirschning*
Institut für Organische Chemie, Leibniz Universität Hannover, Schneiderberg 1b, 30167 Hannover, Germany
e-Mail: andreas.kirschning@oci.uni-hannover.de;
Further Information

Publication History

Received 21 January 2008
Publication Date:
07 April 2008 (online)

Abstract

Coordinative immobilization of an oxime-based palladacycle to poly(vinylpyridine)/glass composite materials shaped as Raschig rings or placed within the PASSflowTM microreactor affords technical devices that are well suited for performing palladium-catalyzed carbon-carbon cross-coupling reactions in the flow-through mode. Reusability of the immobilized precatalyst as well as applications in the microwave field were investigated. Experiments with thiol- and pyridine-based scavengers were carried out, which revealed that the active palladium species is likely to be composed of nanoparticles of unknown nature and that the poly(vinylpyridine) carrier has scavenging properties for these particles.

29

de Vries has demonstrated that Pd nanoparticles can act as active species in solution at extremely low concentrations so that the results presented in Scheme [4] only reflects a kinetic effect.