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Updated: Jun 22, 2025

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions
Published on: July 30, 2017
Silver Complex Bearing N-Heterocyclic Carbene Bidentate Chelating Ligand as an Efficient Catalyst in Solvent-Free KA2
1Department of Organic Chemistry, Faculty of Science, Charles University, Hlavova 8, 128 00, Prague, Czech Republic.
Abstract:
We report a synthesis of silver complexes bearing chelating bidentate N-heterocyclic carbene, with various substitutions at the terminal positions of the imidazole moiety of the NHC units. The long aliphatic substituents proved to be beneficial in terms of the synthetic efficiency of the complexes, compared to previously reported methyl substitution. The complexes demonstrated excellent suitability for the KA2 coupling reaction, providing quaternary carbon-containing propargylic amines in yields up to 95 %, under solvent-free conditions. The method showed high tolerance for a wide range of substrates, including naturally occurring ketones, underscoring its practicality. To our knowledge, this represents the first use of a well-defined silver species in KA2 coupling, marking an advancement in the field.
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