Phase transfer catalyzed aziridination of α-bromo-2-cyclopenten-1-one

An efficient and highly selective synthesis of bicyclic-α-keto aziridines from 2-bromo-2-cyclopentenone and aliphatic primary amines mediated by phase transfer catalysts (PTCs) in water at room temperature is demonstrated. Bicyclic-α-keto-aziridines are highly strained and reactive compounds that can be used in the synthesis of biologically active compounds. Therefore, the present strategy with its mild reaction conditions opens up a new entry to the synthesis of unusual aziridines using inexpensive reagents.