
Abstract
Cyclic diaryl ethers are present in multiple natural compounds, organic pollutants as well as in π-conjugated organic molecular materials. This short review aims at overviewing the main synthetic advances in the O-annulation methods for preparing five-, six-, and seven-membered rings through C–H cleavage.
1 Introduction
2 Five-Membered Rings: The Dibenzofuran (DBF) Motif
2.1 Palladium-Catalysed C–H Activation
2.2 Copper-Catalysed C–H Activation
2.3 Non-CH Activation Oxidant-Mediated Cyclisation
2.4 Light-Mediated Cyclisation
2.5 Acid-catalysed C–O Cleavage/C–O Formation
3 Six-Membered Rings: DBX, PXX, Xanthone, and Their Derivatives
3.1 Dibenzoxanthene (DBX)
3.2 Peri-Xanthenoxanthene (PXX)
3.3 Xanthones
3.4 Miscellaneous
4 Seven-Membered Rings: Cularine
5 Conclusion
Key words
cyclic diaryl ether - oxidative cyclisation - cycloetherification - C–H activation - C–O bond formation - O-annulation - pyrans - furans - cularine