Copper-Catalyzed Trifluoromethylazidation of Alkynes: Efficient Access to CF3-Substituted Azirines and Aziridines

A novel method for convenient access to CF3-containing azirines has been developed, and involves a copper-catalyzed trifluoromethylazidation of alkynes and a photocatalyzed rearrangement. Both terminal and internal alkynes are compatible with the mild reaction conditions, thus delivering the CF3-containing azirines in moderate to good yields. The azirines can be converted into various CF3-substituted aziridines.