Omega-halonitriles: domino cyclizations to oxa- and carbocyclic nitriles

t-BuOK-induced deprotonation of omega-haloalkylnitriles generates remarkably stable potassiated nitriles. In situ deprotonation and alkylation of omega-chloroalkylnitriles with aldehyde electrophiles trigger sequential nucleophilic-electrophilic alkylations generating substituted tetrahydrofuranyl and tetrahydropyranyl nitriles. Redirecting the cyclization manifold with 5-iodopentanenitrile and a ketone causes a complementary electrophilic-nucleophilic cyclization to the corresponding carbonitrile. Collectively these cyclizations provide rapid assembly of five- and six-membered oxa- and carbocyclic nitriles demonstrating the utility of omega-halonitriles in domino alkylations.