New Class of Seven-Membered Heterocycles

  • Author: European Journal of Organic Chemistry
  • Published Date: 04 June 2020
  • Source / Publisher: European Journal of Organic Chemistry/Wiley-VCH
  • Copyright: Wiley-VCH Verlag GmbH & Co. KGaA
thumbnail image: New Class of Seven-Membered Heterocycles

Related Societies

The preparation of heterocyclic compounds is important in synthetic chemistry, e.g., for drug design and materials science. Nuno Maulide and colleagues, University of Vienna, Austria, have discovered a synthesis approach for a new class of fused seven-membered heterocycles (pictured above).

The reaction relies on α‐phthalimido‐amides, which are readily prepared from amino acids in two simple reactions steps. The respective amino acid is first reacted with phthalic anhydride to form the phthalimido group and then with thionyl chloride and HNMe2 to give the desired α‐phthalimido‐amide (pictured below on the left). When these intermediates are reacted with trifluoromethanesulfonic anhydride using 2,6‐di-tert‐butylpyridine (DTBP) as a base and acetonitrile as a solvent, the solvent is incorporated into the resulting fused seven-membered ring system (pictured below). According to the team, this heterocyclic structure had not been accessible so far and represents an entirely new scaffold.

The team studied the mechanism of this unusual reaction, which relies on electrophilic amide activation, and proposed a 5→7 ring enlargement as the key step. Due to the absence of a keteniminium intermediate, the stereogenic information at the α‐position is fully retained. The team will perform further studies on the reactivity of the seven-membered ring products.






Article Views: 2394

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, please contact us first for permission and consult our permisson 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