Total Synthesis of (+)- and (-)-Calycanthine by Means of Thio-Urea-Catalyzed Sequential Michael Reactions of Bis-oxindoles

Arindam Khatua; Debgopal Jana; Monosij Nandy; Pranay Shyamal; Alakesh Bisai

doi:10.1021/acs.joc.4c00019

Total Synthesis of (+)- and (-)-Calycanthine by Means of Thio-Urea-Catalyzed Sequential Michael Reactions of Bis-oxindoles

J Org Chem. 2024 Apr 5;89(7):4792-4801. doi: 10.1021/acs.joc.4c00019. Epub 2024 Mar 28.

Authors

Arindam Khatua¹, Debgopal Jana², Monosij Nandy², Pranay Shyamal², Alakesh Bisai^{1

2}

Affiliations

¹ Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462 066, Madhya Pradesh, India.
² Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Kalyani, Nadia 741 246, West Bengal, India.

PMID: 38544463
DOI: 10.1021/acs.joc.4c00019

Abstract

A unified catalytic asymmetric approach to naturally occurring piperidinoindoline and pyrrololidinoindoline alkaloids has been realized via the development of a thio-urea-catalyzed sequential Michael addition of bis-oxindole onto nitroethylene (up to 93% ee and >20:1 dr). This strategy offers the total syntheses of either enantiomers of naturally occurring calycanthine.