Elimination of an Alkyl Group from Imidazolium Salts: Imidazole‐Coordinated Dinuclear Monodentate NHC–Palladium Complexes Driven by Self‐Assembly and Their Application in the Heck Reaction

A new family of imidazole‐coordinated monodentate NHC–metal complexes 9 was obtained as well as cis ‐chelatedbidentate NHC–metal complexes 10 from novel bis(imidazolium) salts 4 with a biphenyl backbone. The structures of complexes 9a and 10b were determined by X‐ray crystal‐structure diffraction, and their application in the Heck reaction showed good to excellent catalytic activities under very mild conditions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)