Aziridine-2-carboxylates: Preparation, Nucleophilic Ring Opening, and Ring Expansion

Preparation methods of aziridine-2-carboxylates are discussed.The chemical reactivities, focusing on ring opening by various nucleophiles and ring expansion to larger heterocycles, are also surveyed.HETEROCYCLES, Vol.85, No. 12, 2012 R CO 2 Bn N Tr NHTr R CO 2 Bn HO SO 2 Cl 2 , Et 3 N, -50 °C Scheme 2. Preparation of N -Tr-aziridinecarboxylates f rom amino alcohols R = H : 90% R = Me : 94% Activated N-Ts-aziridinecarboxylates were also prepared from N-Ts-(S)-serinate or N-Ts-(S)-threoninate, p-toluenesulfonyl chloride (TsCl), and potassium carbonate (K 2 CO 3 ), under phase-transfer catalyst conditions.The same methodology, when applied to the N-Ts-(S)-serine amide, afforded the corresponding newly prepared aziridinecarboxamide, as an enantiopure compound. 18Unique non-activated 3-arylaziridinecarboxylate formation from guanidinium salts involving an ester