Cooperative N-heterocyclic carbene (NHC)-Lewis acid-mediated regioselective umpolung formal [3 + 2] annulations of alkynyl aldehydes with isatins

Org Biomol Chem. 2014 May 21;12(19):3009-15. doi: 10.1039/c4ob00145a.

Abstract

A novel and regioselective umpolung synthesis of spirooxindoles has been developed by cooperative NHC-Lewis acid-mediated formal [3 + 2] annulations of alkynyl aldehydes with isatins. In most cases, the reactions proceeded via a(3)-d(3) umpolung of alkynyl aldehydes resulting in spirooxindole butenolides. In a few cases, spirooxindole furan-3(2H)-ones were formed as the major products via an a(1)-d(1) umpolung process by controlling the reaction temperature. These newly formed spirooxindoles could provide promising candidates for chemical biology and drug lead discovery.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acids, Heterocyclic / chemistry*
  • Aldehydes / chemistry*
  • Alkynes / chemistry*
  • Catalysis
  • Chemistry, Organic / methods*
  • Crystallography, X-Ray
  • Isatin / chemistry*
  • Lewis Acids / chemistry*
  • Methane / analogs & derivatives*
  • Methane / chemistry
  • Stereoisomerism

Substances

  • Acids, Heterocyclic
  • Aldehydes
  • Alkynes
  • Lewis Acids
  • carbene
  • Isatin
  • Methane