Organocatalytic functionalization of carboxylic acids: isothiourea-catalyzed asymmetric intra- and intermolecular Michael addition--lactonizations

J Am Chem Soc. 2011 Mar 2;133(8):2714-20. doi: 10.1021/ja109975c. Epub 2011 Feb 8.

Abstract

Tetramisole promotes the catalytic asymmetric intramolecular Michael addition-lactonization of a variety of enone acids, giving carbo- and heterocyclic products with high diastereo- and enantiocontrol (up to 99:1 dr, up to 99% ee) that are readily derivatized to afford functionalized indene and dihydrobenzofuran carboxylates. Chiral isothioureas also promote the catalytic asymmetric intermolecular Michael addition-lactonization of arylacetic acids and α-keto-β,γ-unsaturated esters, giving anti-dihydropyranones with high diastereo- and enantiocontrol (up to 98:2 dr, up to 99% ee).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carboxylic Acids / chemistry*
  • Catalysis
  • Cyclization
  • Molecular Structure
  • Pyrones / chemical synthesis*
  • Pyrones / chemistry
  • Stereoisomerism
  • Thiourea / analogs & derivatives*
  • Thiourea / chemistry*

Substances

  • Carboxylic Acids
  • Pyrones
  • Thiourea