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Updated: Oct 1, 2025

Functionalized Spirocyclic Heterocycle Synthesis and Cytotoxicity Assay
Published on: February 9, 2021
Concise total syntheses of bis(cyclotryptamine) alkaloids via thio-urea catalyzed one-pot sequential Michael addition
Arindam Khatua1, Pranay Shyamal2, Souvik Pal1
1Department of Chemistry, IISER Bhopal, Bhopal Bypass Road, Bhopal - 462 066, Madhya Pradesh, India. alakesh@iiserkol.ac.in.
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.
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