Metal Complexes of N-Heterocyclic Carbenes—A New Structural Principle for Catalysts in Homogeneous Catalysis

Authors

  • Prof. Dr. Wolfgang A. Herrmann,

    Corresponding author
    1. Anorganisch-chemisches Institut der Technischen Universität München, Lichtenbergstrasse 4, D-85747 Garching (Germany), Telefax: Int. code + (89)3209-3473
    • Anorganisch-chemisches Institut der Technischen Universität München, Lichtenbergstrasse 4, D-85747 Garching (Germany), Telefax: Int. code + (89)3209-3473
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  • Martina Elison,

    1. Anorganisch-chemisches Institut der Technischen Universität München, Lichtenbergstrasse 4, D-85747 Garching (Germany), Telefax: Int. code + (89)3209-3473
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  • Jakob Fischer,

    1. Anorganisch-chemisches Institut der Technischen Universität München, Lichtenbergstrasse 4, D-85747 Garching (Germany), Telefax: Int. code + (89)3209-3473
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  • Christian Köcher,

    1. Anorganisch-chemisches Institut der Technischen Universität München, Lichtenbergstrasse 4, D-85747 Garching (Germany), Telefax: Int. code + (89)3209-3473
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  • Georg R. J. Artus

    1. Anorganisch-chemisches Institut der Technischen Universität München, Lichtenbergstrasse 4, D-85747 Garching (Germany), Telefax: Int. code + (89)3209-3473
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  • Coordination Chemistry and Mechanisms of Metal-Catalyzed CC Coupling Reactions, Part 9. Part 8: W. A. Herrmann, C. P. Reisinger, K. Öfele, C. Brossmer, M. Beller, H. Fischer, J. Mol. Catal., in press.

Abstract

original image

Stabilized by “carbene” donor ligands, the Pd complex 1 catalyzes the Heck olefination of aryl halides unexpectedly efficiently and yet has long-term stability at elevated temperatures. The active Pd0 species can be generated during the Heck reaction or deliberately prepared by reduction of 1 with, for instance, hydrazine or sodium formate. Another similar catalyst can be synthesized in situ from Pd0 complexes and 1,3-dimethyldihydroimidazoline-2-ylidene.

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