8-aminoquinoline-directed α-amino acids using inexpensive chloroacetonitrile. Iodoacetonitrile generated in situ from chloroacetonitrile reacts with methylene C(sp3)–H bonds of α-amino acids with excellent diastereoselectivity, enabling access to a wide range of important γ-cyano-α-amino acids. Our protocol works well with different aminoacid and carboxylic acid derivatives with good chemical yields