Synlett 2006(18): 2894-2907  
DOI: 10.1055/s-2006-951539
LETTER
© Georg Thieme Verlag Stuttgart · New York

Bridged Imidazolium Salts Used as Precursors for Chelating Carbene Complexes of Palladium in the Mizoroki-Heck Reaction [1]

Tobias Scherg, Sabine K. Schneider, Guido D. Frey, Jürgen Schwarz, Eberhardt Herdtweck, Wolfgang A. Herrmann*
Department Chemie, Lehrstuhl für Anorganische Chemie, Technische Universität München, Lichtenbergstraße 4, 85747 Garching, Germany
Fax: +49(89)28913473; e-Mail: lit@arthur.anorg.chemie.tu-muenchen.de;
Further Information

Publication History

Received 1 June 2006
Publication Date:
25 October 2006 (online)

Abstract

A variety of chiral and achiral imidazolium salts is synthesized. Methylene-, ethylene-, propylene- and pyridinyl-bridged bis(imidazolium) halides are used to generate the respective free chelating carbenes. The synthesis of palladium complexes of general formula [cis-CH2{NC(H)=C(H)N(R)C}2PdX2] with these chelating N-heterocyclic carbene ligands is reported. Structural proofs of complexes 28 and 46 are represented by X-ray diffraction studies. Catalytic applications in the Mizoroki-Heck reaction are presented.

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