Ring expansion strategy to access functionalized 2-oxazolines (microreview)

The development of innovative methods for the construction of heterocycles is an important topic in synthetic and medicinal chemistry. Ring expansion strategies, involving the cyclization of strained aza rings, have been well developed in the synthesis of diverse heterocyclic compounds. This microreview summarizes recent advances in the ring expansion reactions of aziridines, oxetanes, and azetidines to access a series of functionalized 2-oxazolines, which are versatile structural motifs in drugs and bioactive molecules.