ACTIVATION OF COORDINATED TRIMETHYLACETONITRILE IN DI-IRON mu-AMINOCARBYNE COMPLEXES

In spite of the fact that nitriles are generally considered substitution labile ligands, their coordination to metal centers often results in a enhanced susceptibility of the C atom toward nucleophilic attack. As a part of our interest in nucleophilic addition to diiron-mu-aminocarbyne complexes, here we report on the reaction of LiCCtol (tol=C6H4Me) with [Fe2{mu-CN(Me)Me2C6H3}(mu-CO)(CO)(NCtbu)(Cp)2]SO3CF3 1 affording the metallacycle complex 2. The reaction proceeds via acetylide addition at the coordinated trimethylacetonitrile as indicated by the isolation of the imine complex [Fe2{mu-CN(Me)Me2C6H3}(mu-CO)(CO){NHC(CCtol)tbu})(Cp)2]SO3CF3, obtained upon treatment of the reaction mixture with HSO3CF3, immediately after the addition of LiCCtol.