Edge-Extended Kekulenes

  • Author: ChemistryViews
  • Published: 22 August 2021
  • Copyright: Wiley-VCH GmbH
  • Associated Societies: American Chemical Society (ACS), USA
thumbnail image: Edge-Extended Kekulenes

Kekulene is a cycloarene, i.e., a macrocycle composed of benzene units. Kekulene has a hexagonal structure with three benzene units at each edge. Extending these edges with further benzene rings would lead to [m,n]cycloarenes, with m and n equal to the numbers of benzene units on two adjacent edges. In this notation, kekulene derivatives are denoted as [3,3]cycloarenes.

Jishan Wu, National University of Singapore and Joint School of National University of Singapore and Tianjin University, Fuzhou, China, and colleagues have synthesized [m,n]cycloarene derivatives with extended edges, i.e., [3,4]-, [3,5]-, [4,4]-, and [4,5]cycloarenes (latter pictured above). The team first prepared suitable macrocyclic precursors functionalized with vinyl ethers using Suzuki coupling reactions. Then, they used a bismuth(III) triflate-catalyzed cyclization reaction to close the remaining six-membered rings and obtain the desired cycloarenes.

The products were characterized using X-ray crystallography and NMR spectroscopy, as well as density functional theory (DFT) calculations. The team found that the π-electrons in the compounds' macrocyclic cores are mainly delocalized within individual benzene, naphthalene, or anthracene units at the edges (pictured in blue in the example above).



Article Views: 3147

Sign in Area

Please sign in below

Additional Sign In options

Please note that to comment on an article you must be registered and logged in.
Registration is for free, you may already be registered to receive, e.g., the newsletter. When you register on this website, please ensure you view our terms and conditions. All comments are subject to moderation.

Article Comments - To add a comment please sign in

If you would like to reuse any content, in print or online, from ChemistryViews.org, please contact us first for permission and consult our permission guidance prior to making your request

Follow on Facebook Follow on Twitter Follow on YouTube Follow on LinkedIn Follow on Instagram RSS Sign up for newsletters

Magazine of Chemistry Europe (16 European Chemical Societies) published by Wiley-VCH