All-carbon N-heterocyclic carbene-catalyzed (3+2) annulation using donor-acceptor cyclopropanes

Lisa Candish, Rachel M. Gillard, Jared E. M. Fernando, Alison Levens, David W. Lupton

Research output: Contribution to journalReview ArticleResearchpeer-review

9 Citations (Scopus)

Abstract

Donor-acceptor cyclopropanes are known to serve as dipole precursors capable of engaging in (3+2) annulations with electron-deficient π-systems. In 2013, the reaction of donor-acceptor cyclopropanes with α,β-unsaturated acyl fluorides in an all-carbon (3+2) annulation was discovered. The reaction proceeds in good yields using the IMes NHC to provide diastereomerically pure β-lactone-fused cyclopentanes bearing four contiguous stereocentres. Subsequent studies demonstrated that N-t-butyl substituted homochiral morpholinone NHCs allowed the reaction to be achieved in up to 98 % ee. In this account, a background to this reaction is introduced, along with a complete account of the strengths, limitations and challenges encountered while developing this chemistry.

Original languageEnglish
Pages (from-to)522-530
Number of pages9
JournalIsrael Journal of Chemistry
Volume56
Issue number6-7
DOIs
Publication statusPublished - 1 Jun 2016

Keywords

  • annulation
  • cyclopentane
  • donor-acceptor cyclopropanes
  • enantioselectivity
  • N-heterocyclic carbene

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