Visible Light-Promoted Construction of Cage-Like Frameworks by Sequential [2 + 2] Cycloaddition
Zhuhai Zhang1, Yu Feng1, Jianfu Chen2
1School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China.
Organic Letters
|June 21, 2025
Summary
Researchers developed a novel visible light-promoted cycloaddition reaction for synthesizing unique cage-like molecules. This efficient method offers a one-step pathway to complex structures with high selectivity and functional group tolerance.
Area of Science:
- Organic Chemistry
- Photochemistry
- Synthetic Methodology
Background:
- Medium-ring frameworks are prevalent in natural products and pharmaceuticals.
- Efficient and selective synthetic routes to these structures are highly sought after.
- Cycloaddition reactions are powerful tools for constructing cyclic systems.
Purpose of the Study:
- To develop a novel sequential [2 + 2] cycloaddition reaction.
- To synthesize unprecedented cage-like medium-ring frameworks.
- To establish a mild, atom-economical, and highly selective synthetic method.
Main Methods:
- Visible light irradiation
- Photosensitization
- Sequential [2 + 2] cycloaddition of unsaturated N-acylindoles
- Mechanistic studies (experimental and computational)
Main Results:
- Formation of unprecedented cage-like medium-ring frameworks in high yields.
- Exclusive regio- and diastereoselectivity achieved.
- Excellent functional group tolerance and mild reaction conditions demonstrated.
- Reaction proceeds via an energy transfer pathway in a double [2 + 2] cycloaddition process.
Conclusions:
- A novel and efficient visible light-promoted sequential [2 + 2] cycloaddition has been developed.
- This methodology provides a facile, single-step access to complex cage-like molecules.
- The reaction mechanism involves an energy transfer pathway, highlighting the role of photoredox catalysis.
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