Palladium-Catalyzed Dearomative [4 + 2]-Cycloaddition toward Hydrocarbazoles.

J Org Chem

Medicinal & Process Chemistry Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, P.O. Box 173, Lucknow 226031, Uttar Pradesh, India.

Published: January 2023

An efficient method for the construction of hydrocarbazoles bearing three continuous sterically hindered stereocenters, two quaternary and one tertiary, via a highly diastereoselective palladium-catalyzed [4 + 2]-cycloaddition/dearomatization of 3-nitroindoles has been developed. The cycloaddition of 3-nitroindoles occurs at ambient conditions with a 1,4-zwitterionic intermediate, in situ generated from γ-methylidene-δ-valerolactones. The further synthetic utility of this method is demonstrated by the multifaceted transformations possible from the products. The catalytic asymmetric aspect of this transformation has also been explored.

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http://dx.doi.org/10.1021/acs.joc.2c01869DOI Listing

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