Synthesis and catalytic properties of novel ruthenium N-heterocyclic-carbene complexes

The reaction of [RuCl2(p-cymene)]2 with 1,3-dialkylimidazolinium salts 1a–f in the presence of a small excess of cesium carbonate yields chelated η6-arene, η1-carbene ruthenium complexes 2a–f. All synthesised compounds were characterized by elemental analysis, NMR spectroscopy. The catalytic activity of RuCl2(η6-arene, η1-imidazolinylidene) complexes 2a–f was evaluated in the direct arylation of 2-phenylpyridine with chlorobenzene derivatives.