Converting Strain Release into Aromaticity Loss for Activation of Donor-Acceptor Cyclopropanes: Generation of Quinone Methide Traps for C-Nucleophiles
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Updated: Jun 13, 2025
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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Vitaly V Shorokhov1, Beauty K Chabuka2, Timur P Tikhonov1
1Department of Chemistry, M. V. Lomonosov Moscow State University, Leninskie gory 1-3, Moscow 119991, Russia.
Abstract:
Here, we present a new approach for the activation of donor-acceptor cyclopropanes in ring-opening reactions, which does not require the use of a Lewis or Brønsted acid as a catalyst. Donor-acceptor cyclopropanes containing a phenolic group as the donor undergo deprotonation and isomerization to form the corresponding quinone methides. This innovative strategy was applied to achieve (4 + 1)-annulation of cyclopropanes with sulfur ylides, affording functionalized dihydrobenzofurans. Additionally, the generated ortho- and para-(aza)quinone methides can be trapped by various CH-acids.
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