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Oxidative Addition of Haloheteroarenes to Palladium(0): Concerted versus SNAr‐Type Mechanism |
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| Authors: | Prof Bert U W Maes Dr Stefan Verbeeck Dr Tom Verhelst Audrey Ekomié Niklas von?Wolff Dr Guillaume Lefèvre Dr Emily A Mitchell Prof Anny Jutand |
| Affiliation: | 1. Organic Synthesis, Department of Chemistry, University of Antwerp, 2020 Antwerpen (Belgium);2. Ecole Normale Supérieure‐PSL Research University, Département de Chimie, Sorbonne Universités, UPMC Univ Paris 06, CNRS UMR 8640 PASTEUR, 24 Rue Lhomond, 75231 Paris Cedex 5 (France);3. CEA‐Saclay, IRAMIS Institute, SIS2M/NIMBE/LCMCE, 91191 Gif Sur Yvette, Cedex (France) |
| Abstract: | The kinetics of the oxidative additions of haloheteroarenes HetX (X=I, Br, Cl) to Pd0(PPh3)2] (generated from Pd0(PPh3)4]) have been investigated in THF and DMF and the rate constants have been determined. In contrast to the generally accepted concerted mechanism, Hammett plots obtained for substituted 2‐halopyridines and solvent effects reveal a reaction mechanism dependent on the halide X of HetX: an unprecedented SNAr‐type mechanism for X=Br or Cl and a classical concerted mechanism for X=I. These results are supported by DFT studies. |
| Keywords: | arenes homogeneous catalysis kinetics oxidative addition reaction mechanisms |
