Aldimines (generated in situ from aldehydes and amines) react readily with ethyl diazoacetate in the presence of 2 mol% of Bi(OTf)3 or 5 mol% of Sc(OTf)3 in [bmim]PF6 ionic liquid to produce the corresponding aryl aziridine carboxylates in high yields with excellent cis-diastereoselectivity. The recovered ionic liquid containing catalyst was reused in three to four subsequent runs with gradual decrease in activity.