Enantioselective Construction of Spirooxindole-Fused Cyclopenta[c]chromen-4-ones Bearing Five Contiguous Stereocenters via a Stepwise (3+2) Cycloaddition

Sandip Sambhaji Vagh, Praneeth Karanam, Cheng Chieh Liao, Ting Han Lin, Yan Cheng Liou, Athukuri Edukondalu, Yi Ru Chen, Wenwei Lin

Research output: Contribution to journalArticlepeer-review

Abstract

The bifunctional quinine-catalyzed stepwise (3+2) cycloaddition for the enantioselective construction of spirooxindole-fused cyclopenta[c]chromen-4-ones is developed. The reactions of 3-homoacylcoumarins and alkylidene oxindole electrophiles generate aforementioned spirooxindole-chromenone adducts bearing five contiguous stereocenters, of which one is the spiro all-carbon quaternary stereocenter in high yields (up to 99%) with excellent stereoselectivities (up to >20:1 dr and 99% ee). This methodology was investigated for three different alkylidene oxindole electrophiles and could also be practically demonstrated on a gram scale. Mechanistic investigations revealed that the (3+2) cycloaddition for the enantioselective synthesis of spirooxindole-fused cyclopenta[c]chromen-4-ones is proceeding via a stepwise reaction pathway. (Figure presented.).

Original languageEnglish
Pages (from-to)1679-1685
Number of pages7
JournalAdvanced Synthesis and Catalysis
Volume362
Issue number8
DOIs
Publication statusPublished - 2020 Apr 17

Keywords

  • 3-homoacylcoumarins
  • cyclopenta[c]chromen-4-ones
  • organic catalysis
  • spiro compounds
  • stepwise (3+2) cycloaddition

ASJC Scopus subject areas

  • Catalysis
  • Organic Chemistry

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