Recent breakthroughs in ring-opening annulation reactions of aziridines.

Aziridines, characterized by their highly constrained three-membered nitrogen-containing heterocyclic ring system, serve as compelling synthetic intermediates for synthesizing numerous naturally occurring alkaloids and pharmaceuticals. The distinct ring strain arising from the geometric constraints of these sp-rich trigonal rings imparts high reactivity, thereby offering a wealth of intriguing synthetic opportunities. Recent advances in the chemistry and reactivity of aziridines have unveiled significant progress in preparing more complex heterocycles. This review consolidates and examines recent publications on the ring-opening annulation reactions of aziridines, highlighting the latest breakthroughs, emerging trends, and future directions in this dynamic field.