The proton(s) α to the nitrile group are sufficiently acidic that they undergo deprotonation by strong bases, usually lithium-derived.
Additionally, deprotonated cyanohydrins can act as masked acyl anions, giving products impossible to access with enolates alone.
[2][3] Nitrile anions can also be involved in Michael-type additions to activated double bonds and vinylation reactions with a limited number of polarized, unhindered acetylene derivatives.
These intermediates almost always react with α selectitivity in alkylation reactions, the exception to the rule being anions of ortho-tolyl nitriles.
Although intermolecular arylations using nitrile anions result in modest yields, the intramolecular procedure efficiently gives four-, five-, and six-membered benzo-fused rings.
[11] Polyanions of nitriles can also be generated by multiple deprotonations, and these species produce polyalkylated products in the presence of alkyl electrophiles.
[12] Alkylation of a nitrile anion followed by reductive decyanation was employed in the synthesis of (Z)-9-dodecen-1-yl acetate, the sex pheromone of Paralobesia viteana.