Palladium complexes containing potentially chelating pyridylidene-type carbene ligands

Poulain, Aurélie; Neels, Antonia; Albrecht, Martin

doi:10.1002/ejic.200801155

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Journal article

Palladium complexes containing potentially chelating pyridylidene-type carbene ligands

Poulain, Aurélie Department of Chemistry, University of Fribourg, Switzerland
Neels, Antonia CSEM Center Suisse d'Electronique et de Microtechnique, Neuchâtel, Switzerland
Albrecht, Martin Department of Chemistry, University of Fribourg, Switzerland

12.03.2009

Published in:

European Journal of Inorganic Chemistry. - 2009, no. 13, p. 1871 - 1881

English Oxidative addition of 2-bromopyridine derivatives containing a potentially chelating donor group E (E = NMe₂, SMe, SPh) to palladium(0) gives C,E-bound pyridylpalladium(II) complexes. Mono-, di-, and polymeric palladium complexes are obtained depending on the type of functionalization at the pyridyl nitrogen. With a lone pair at nitrogen, dimetallic products are isolated, while protonation gives monometallic pyridylidene-type complexes. Remarkably, N-methylation inhibits chelating ligand coordination and a one-dimensional polymer is formed instead. Heck-type arylation of styrene is used as a probe for the catalytic activity of the palladium pyridylidene complexes and reveals moderate activities. Mechanistic studies support a heterogeneous mode of action, including loss of the pyridylidene-type ligand from the metal coordination sphere.

Faculty

Faculté des sciences et de médecine

Department

Département de Chimie

Language