Reactivity of Amido Ligands on a Dinuclear Ru(II) Center: Formation of Imido Complexes and C−N Coupling Reaction with Alkyne

Treatment of a dinuclear Ru(II) amido complex [Cp*Ru(μ2-NHPh)]2 (Cp* = η5-C5Me5) with small organic substrates including CO, tert-butyl isocyanide, a sulfur ylide Ph2SCH2, and diphenylacetylene resulted in an unexpected disproportionation reaction of the bridging amido ligands to produce a free amine and a series of imido-bridged diruthenium complexes [(Cp*Ru)2(μ2-L)(μ2-NPh)] (L = CO, t-BuNC, CH2). In the case of diphenylacetylene, the bridging imido ligand underwent subsequent coupling reaction with the coordinated alkyne to form an iminoalkenyl complex [(Cp*Ru)2(μ2-PhNCPhCPh)].