Cobalt-catalyzed cross addition of silylacetylenes to internal alkynes

J Org Chem. 2013 Apr 19;78(8):3583-91. doi: 10.1021/jo400064b. Epub 2013 Apr 1.

Abstract

A CoCl2·6H2O/Zn reagent using 2-(2,6-diisopropylphenyl)iminomethylpyridine (dipimp), 1,2-bis(diphenylphosphino)ethane (dppe), or 1,2-bis(diphenylphosphino)benzene (dppPh) as a ligand effectively catalyzed the cross-addition reaction of silylacetylene to internal alkynes. The reaction of some unsymmetrical internal alkynes, such as 3-arylpropargyl alcohols, proceeded in a highly regioselective manner in the presence of dppe or dppPh but gave a nearly 1:1 mixture of regioisomers in the presence of dipimp. The results of reactions using 1-deuterated 2-silylacetylene revealed that the reaction involves a direct oxidative addition of the silylacetylenic C-H bond to cobalt.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkynes / chemistry*
  • Benzene Derivatives / chemistry*
  • Catalysis
  • Cobalt / chemistry*
  • Hydrogen Bonding
  • Indicators and Reagents / chemistry*
  • Ligands
  • Molecular Structure
  • Organophosphonates / chemistry*
  • Organosilicon Compounds / chemistry*
  • Oxidation-Reduction
  • Stereoisomerism

Substances

  • 1,2-bis(diphenylphosphino)benzene
  • Alkynes
  • Benzene Derivatives
  • Indicators and Reagents
  • Ligands
  • Organophosphonates
  • Organosilicon Compounds
  • Cobalt