Synthesis, structure and catalytic properties of [Ru(dppp)2(CH3CN)Cl][BPh4] and isolation of catalytically active [Ru(dppp)2Cl][BPh4]: ruthenium catalysed alkyne homocoupling and tandem alkyne-azide cycloaddition

The compound, [Ru(dppp)(2)(CH3CN)Cl][BPh4] (1) has been synthesised from the precursor complex, [Ru(PPh3)(3)Cl-2]. The complex has been structurally characterised. The complex has been found to be an efficient catalyst for the homocoupling of alkynes in the presence of silver salts. The complex can also catalyse homocoupling of alkynes and subsequent alkyne-azide cycloaddition. The catalytically active species, [Ru(dppp)(2)Cl][BPh4] (2) and one of the intermediate complexes, [Ru(dppp)(2)(CCPh)(2)] (6), have been isolated and structurally characterised.