RUTHENIUM(II)-MEDIATED REACTION OF PHENYLACETYLENE WITH PRIMARY AMINES TO GIVE RUTHENIUM(II)-ISONITRILE COMPLEXES

The Ru(II) fragment [(PNP)RuCl2] assists the reaction of phenylacetylene with a variety of primary amines, including optically pure amines, to give Ru(II)isonitrile complexes (PNP = CH3CH2CH2N(CH2CH2-Ph(2))(2)). The reaction is initiated by 1-alkyne to vinylidene tautomerization at the ruthenium center, followed by attach of the primary amine on the vinylidene ligand to give Ru(II) aminocarbenes of the formula fac,cis-[(PNP)RuCl2{=C(NHR)(CH(2)Ph)}]. The latter compounds thermally convert to the corresponding isonitrile complexes fac,cis-[(PNP)RuCl2(CNR)], while toluene is eliminated via C-C bond cleavage (R = CH2CH2CH3, cyclo-C6H11, (R)-(+)-CH(Me)(Ph), (R)-(-)-CH(Me)(Et), (S)-(-)-CH(Me)(1-naphthyl)].