The stereochemistry of electrophilic substitutions of α‐nitrile metallocarbanions is probed through the deprotonation of enantioenriched α‐amino‐ and α‐oxynitriles bearing a carbamoyl or methoxycarbonyl group. The dipole‐stabilizing substituents affect the configurationalstability and reactivity of the α‐nitrile metallocarbanions and also change the steric course (retention vs. inversion).