Regioselective Synthesis of Vicinal Diamines by Pr(OTf) 3 ‐Catalyzed Intermolecular Aminolysis of N ‐Alkyl‐2,3‐Aziridinyl Alcohols

Vicinal diamine motifs are found in a wide variety of bioactive molecules and act as valuable ligands for transition‐metal catalysts. Aminolysis of aziridines is a direct and atom‐economical synthesis approach to these structural units; however, controlling the regioselectivity of the intermolecular ring opening of nonactivated aziridines remains challenging. Herein, we report a Pr(OTf) 3 ‐catalyzed regioselective intermolecular aminolysis of N ‐alkyl‐2,3‐aziridinyl alcohols. In benzotrifluoride, various aliphatic and aromatic amines undergo selective nucleophilic attack at the C3 position to afford the corresponding vicinal diamines. Investigation of O ‐protected and N ‐protected substrates suggests that bidentate coordination of the lanthanide catalyst to the free hydroxy group and alkylated aziridine nitrogen plays a key role in achieving the observed regioselectivity.