Ruthenium-catalyzed asymmetric [2 + 2] cycloadditions between chiral acyl camphorsultam-substituted alkynes and bicyclic alkenes

J Org Chem. 2014 Nov 7;79(21):10002-12. doi: 10.1021/jo501594g. Epub 2014 Oct 21.

Abstract

Ruthenium-catalyzed asymmetric [2 + 2] cycloadditions between chiral acyl camphorsultam-functionalized alkynes and bicyclic alkenes were examined, providing adducts with complete exo stereoselectivity in good overall yield and enantioselectivity (up to 99% and 166:1, respectively), as well as appreciable diastereoselectivity (up to 163:1). The diastereoselectivity showed dependence on the solvent and temperature, as well as on the substitution pattern of the reacting alkyne and bicyclic alkene components. In general, higher diastereoselectivities were observed for reactions conducted in ethereal solvents and at lower temperatures between N-propynoyl camphorsultams and bicyclic alkenes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkenes / chemistry*
  • Alkynes / chemistry*
  • Bridged Bicyclo Compounds / chemistry*
  • Catalysis
  • Cycloaddition Reaction
  • Heterocyclic Compounds, 3-Ring / chemistry*
  • Molecular Structure
  • Ruthenium / chemistry*
  • Stereoisomerism

Substances

  • Alkenes
  • Alkynes
  • Bridged Bicyclo Compounds
  • Heterocyclic Compounds, 3-Ring
  • camphorsultam
  • Ruthenium