A cinchona alkaloid catalyzed enantioselective sulfa-Michael/aldol cascade reaction of isoindigos: construction of chiral bispirooxindole tetrahydrothiophenes with vicinal quaternary spirocenters

Org Biomol Chem. 2015 Jun 14;13(22):6371-9. doi: 10.1039/c5ob00774g.

Abstract

A cinchona alkaloid catalyzed diastereoselective and enantioselective sulfa-Michael/aldol cascade reaction between 1,4-dithiane-2,5-diol and isoindigos has been successfully developed to afford the highly congested bispirooxindole tetrahydrothiophenes with vicinal quaternary spirocenters in high yields (up to 91%), excellent diastereoselectivities (up to >20 : 1 dr), and good enantioselectivities (up to 98% ee). Some synthetic transformations of the reaction products were also studied.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Cinchona Alkaloids / chemistry*
  • Crystallography, X-Ray
  • Indoles / chemical synthesis*
  • Indoles / chemistry
  • Models, Molecular
  • Molecular Structure
  • Spiro Compounds / chemical synthesis*
  • Spiro Compounds / chemistry
  • Stereoisomerism
  • Thiophenes / chemical synthesis*
  • Thiophenes / chemistry

Substances

  • Cinchona Alkaloids
  • Indoles
  • Spiro Compounds
  • Thiophenes
  • isoindigotin