Synthesis and Reactivity of 2-Arylquinazoline Halidoruthenacycles in Arylation Reactions

We have synthesized a range of novel cyclometallated organoruthenium(II) complexes through ortho-C-H activation of the aryl group in 2-aryl-substituted quinazolines with [RuX2(p-cymene)]2. The beneficial effect of the carboxylate ligand on both the cyclometallation and further arylation reaction step was demonstrated. Mechanistic studies reveal that bromide and iodide anions decelerates the arylation process via in situ ligand exchange reaction. Additionally, a detailed NMR investigation explains some elementary steps in the arylation of 2-(aryl)quinazoline-halido-ruthenacycles.