Cascade Energy-Transfer-Mediated [2 + 2] Cycloaddition/Ring-Expansion Rearrangement of Indole Derivatives via Vinylcyclobutane Intermediates
Abstract
Vinylcyclobutane-based rearrangements hold great potential for molecular reorganization, yet their application in cascade reactions remains largely underexplored. Herein, we report a cascade energy-transfer-catalyzed rearrangement involving vinylcyclobutanes derived from indole frameworks, enabling the synthesis of pharmaceutically relevant carbazole derivatives. Mechanistic investigations confirm that the reaction proceeds through a cascade energy-transfer pathway involving sequential excitation of both the starting material and the in situ-generated cyclobutane intermediate. This work offers valuable insights into the design of vinylcyclobutane-based cascade transformations and the construction of architecturally complex polycyclic scaffolds.
Fields of Study & Subjects
Catalytic C–H Functionalization Methods
Cyclopropane Reaction Mechanisms
Radical Photochemical Reactions
Publication details
- Journal / source
- Organic Letters
- Publisher
- American Chemical Society (ACS)
- Volume
- 28
- Issue
- 20
- Pages
- 6468–6472
- Publication date
- 13 May 2026
- Language
- EN