An organocatalytic synthesis of cis-N-alkyl- and N-arylaziridine carboxylates

An extremely mild protocol that employs readily available starting materials, i.e., aldehyde, amine and alkyl diazoacetate, returns structurally diverse N-substituted-C-2/3-difunctionalised aziridines in excellent yields and stereoselectivities when pyridinium triflate is incorporated as an organocatalyst. The reaction process is environmentally benign affording water and nitrogen as the only by-products. This racemic protocol paves the way for the development of novel asymmetric organocatalysts capable of generating optically active aziridines.