Metalated Nitriles: Organolithium, -magnesium, and -copper Exchange of α-Halonitriles

α-Halonitriles react with alkyllithium, organomagnesium, and lithium dimethylcuprate reagents generating reactive, metalated nitriles. The rapid halogen−metal exchange with alkyllithium and Grignard reagents allows selective exchange in the presence of reactive carbonyl electrophiles, including aldehydes, providing a high-yielding alkylation protocol. Lithiated and magnesiated nitriles react with propargyl bromide by SN2 displacement whereas organocopper nitriles react by SN2‘ displacement, correlating with the formation of a C-metalated nitrile.