From six- to five-membered heterocycles via ring contraction in the last quarter century

Key Points

• Five-membered heterocycles resulted from enhanced ring contraction methods in recent decades, transforming synthetic chemistry.
• Key innovations involve various synthetic pathways developed over the last 25 years to facilitate ring contraction.
• The analysis reviews reaction mechanisms that have evolved, providing insights into the efficiency of these processes.
• Implications suggest that these advancements may improve the efficiency of drug synthesis and materials science applications.