Harnessing Light for Strain Release: Light‐Driven Transformations of Azabicyclo[1.1.0]butanes

Azabicyclo[1.1.0]butanes (ABBs) have emerged as promising strained intermediates for the synthesis of azetidines and other nitrogen‑containing heterocycles with considerable relevance to medicinal chemistry. Recent advances in photocatalytic approaches have enabled efficient and selective transformations of ABBs under mild conditions, opening new routes to structurally diverse, three‑dimensional scaffolds. This review summarizes recent developments in light‑driven transformations of ABBs. The mechanistic underpinnings, substrate scope, and synthetic utility of these methods are discussed, underscoring the growing role of photochemistry in harnessing strain‑release reactivity for the construction of bioactive azetidine derivatives, 1‑azabicyclo[2.1.1]hexanes, and 1‑azabicyclo[4.1.1]octenes.