Synthesis, Characterization and Catalytic Activity of New N‐Heterocyclic Bis(carbene)ruthenium Complexes

Abstract

Abstract The reaction of RuCl 2 (PPh 3 ) 3 with t BuOK‐deprotonated ortho ‐xylyl‐bis( N ‐imidazolinium) salts 1a – d yields RuCl 2 (PPh 3 )[bis(imidazolidin‐2‐ylidene)] complexes ( 2a – d ). Under similar conditions, [RuCl 2 ( p ‐cymene)] 2 leads to the ruthenium complex 3 containing a tridentate η 6 ‐arene‐dicarbene ligand. All synthesized compounds were characterized byelemental analysis and NMR spectroscopy, and the molecular structures of 2a , 2b and 3 were determined by X‐ray crystallography. The catalytic activity of RuCl 2 (PPh 3 )[bis(imidazolidin‐2‐ylidene)] complexes 2a – b was evaluated in the direct arylation of 2‐phenylpyridine with chlorobenzene derivatives. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)