Iron–cobalt-catalyzed heterotrimerization of alkynes and nitriles to polyfunctionalized pyridines

Based on the reactivity of half-sandwich complexes [Cp*Fe(NCMe) 3 ]PF 6 and Cp*Co(1,2-Ph 2 PC 6 H 4 NH), (Cp* = Me 5 C 5 − ), the iron( ii )–cobalt( ii ) co-catalysis of the cycloaddition of alkynes to nitriles under mild reaction conditions has been studied. This method enables the synthesis of polysubstituted pyridines in a single step, and is especially valuable for the preparation of 2,3,4,5,6-pentafunctionalized pyridines.