Concise total syntheses of bis(cyclotryptamine) alkaloids via thio-urea catalyzed one-pot sequential Michael addition

Chem Commun (Camb). 2022 Mar 22;58(24):3929-3932. doi: 10.1039/d2cc01008a.

Abstract

Naturally occurring bis(cyclotryptamine) alkaloids feature vicinal all-carbon quaternary stereocenters with an elongated labile C-3a-C-3a' Sigma bond with impressive biological activities. In this report, we have developed a thio-urea catalyzed one-pot sequential Michael addition of bis-oxindole onto selenone to access enantioenriched dimeric 2-oxindoles with vicinal quaternary stereogenic centers at the pseudobenzylic position (up to 96% ee and >20 : 1 dr). This strategy has been successfully applied for the total syntheses of either enantiomers of chimonanthine, folicanthine, and calycanthine.

MeSH terms

  • Alkaloids* / chemistry
  • Catalysis
  • Molecular Structure
  • Stereoisomerism
  • Urea*

Substances

  • Alkaloids
  • Urea