Photoexcited Intramolecular Annulative Cross-Coupling via an EDA Complex Mechanism
Abstract
Transition-metal-free cross-coupling reactions have emerged as an important green and sustainable methodology in modern organic synthesis. Herein, we report a metal- and additive-free strategy for the intramolecular C–halogen/C–H cross-coupling to construct phenanthrene cores. This method employs readily accessible E/Z -mixed diarylethenes, which involve a rapid E → Z isomerization followed by radical cyclization under mild conditions. Mechanistic studies support a chain pathway involving Z/E photoisomerization followed by electron donor–acceptor (EDA) complex-mediated single-electron transfer (SET) and radical cyclization. This work provides a practical route to phenanthrene cores while offering detailed mechanistic insights into metal-free, photoinduced C(Ar)–halogen bond activation.
Fields of Study & Subjects
Radical Photochemical Reactions
Catalytic C–H Functionalization Methods
Photochromic and Fluorescence Chemistry
Publication details
- Journal / source
- Organic Letters
- Publisher
- American Chemical Society (ACS)
- Volume
- 28
- Issue
- 21
- Pages
- 6803–6809
- Publication date
- 14 May 2026
- Language
- EN