Soluble organocobalt catalysts permit selective formation of substituted pyridines under mild conditions in a single step: mono-, di-, and trisubstituted pyridines can be obtained at will in high conversions and high yields from nitriles and alkynes. Polynuclear derivatives such as bipyridines can also be prepared by this method.
(b)Prior to the initiation of catalysis, a small amount of a suitable cobalt salt is dissolved or suspended in the substrate Angew. Chem. Int. Ed. Engl. 17, 505-515 (1978)