芳香環メタモルフォシス

Aromatic skeletons are typically considered resistant to cleavage due to their high aromatic stabilization energy as well as strong bonds between adjacent endocyclic atoms. While exocyclic functionalizations of aromatic compounds have garnered significant attention, endocyclic modifications of aromatic cores—achieved through partial disassembly of the cyclic skeletons followed by ring reconstruction—have received less focus. Here, we detail our endeavors to establish 'aromatic metamorphosis', wherein common aromatic compounds like thiophenes, benzofurans, and indoles are transformed into distinct ring systems in a multi-step strategy or ideally a one-step transformation. Aromatic metamorphosis challenges conventional notions in organic chemistry and introduces a revolutionary approach to organic synthesis. It opens up new avenues for the synthesis of intriguing heterocycles that were previously challenging to synthesize and for the generation of chemical libraries enriched with endocyclic diversity.