Cycloisomerization of acetylenic acids to γ-alkylidene lactones using a palladium(II) catalyst supported on amino-functionalized siliceous mesocellular foam

J Org Chem. 2014 Feb 7;79(3):1399-405. doi: 10.1021/jo4028006.

Abstract

Cycloisomerization of various γ-acetylenic acids to their corresponding γ-alkylidene lactones by the use of a heterogeneous Pd(II) catalyst supported on amino-functionalized siliceous mesocellular foam is described. Substrates containing terminal as well as internal alkynes were cyclized in high to excellent yields within 2–24 h under mild reaction conditions. The protocol exhibited high regio- and stereoselectivity, favoring the exo-dig product with high Z selectivity. Moreover, the catalyst displayed excellent stability under the employed reaction conditions, as demonstrated by its good recyclability and low leaching.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkynes / chemistry*
  • Amines / chemistry*
  • Catalysis
  • Cyclization
  • Lactones / chemistry*
  • Molecular Structure
  • Palladium / chemistry*
  • Silicon Dioxide / chemistry*
  • Stereoisomerism

Substances

  • Alkynes
  • Amines
  • Lactones
  • Palladium
  • Silicon Dioxide