Switchable reactivity of 2-Azetines: Ionic versus radical pathway for accessing β-aminocarbonyls and 2,3-disubstituted azetidines

Abstract. Two unprecedented transformations of 2-azetines are reported. Varied C2-functionalized 2-azetines, prepared under continuous flow conditions, acted as linchpin for the preparation of either -aminocarbonyls or C3-thiolated azetidines. Interestingly, the two transformations occurred following an ionic or radical pathway depending on the reaction conditions. The ionic pathway is triggered under acidic conditions in the presence of water, while the radical process is initiated using white light irradiation following a thiol-ene reactive scheme. These two methods have been applied to the synthesis of several products including bioactive fragments. Mechanistic evidence for the two pathways is provided.