Oxetanes in heterocycle synthesis: recent advances

Owing to their balanced ring strain and the high regioselectivity of their reactions, oxetanes have emerged as versatile building blocks for heterocycle synthesis. This review summarizes representative advances (2019-2025) in heterocycle construction using oxetanes, categorized by different reaction types: nucleophilic attack-induced ring-opening (further subdivided into direct intramolecular nucleophilic ring-opening and tandem reactions that integrate intermolecular coupling with subsequent intramolecular ring-opening), semipinacol rearrangements, 2-vinyl oxetanes serving as 1,6-dipole precursors and other novel synthetic strategies. For each category, the core reaction mechanisms, chiral control approaches (where applicable), and substrate scope of representative studies are discussed. This review aims to highlight the construction of heterocycles involving oxetanes over the past five years and offer insights to guide future research in heterocycle synthesis.