Primary‐Amine‐Specific Lactamization of ω‐Amino Acids by an Artificial Cyclotransferase Based on [18]Crown‐6

Feet first: Carboxylic acids with a primary amino group in the farthest position from the carboxy group are specifically bound to an artificial cyclotransferase based on [18]crown-6. The amino group fits into the [18]crown-6 substrate-binding site to bring the carboxyl group close to the 2-ammonio-1,3,5-triazine reaction site for selective conversion into a lactam.