Nickel-catalyzed substitution reactions of propargyl halides with organotitanium reagents

Org Biomol Chem. 2014 Oct 14;12(38):7634-42. doi: 10.1039/c4ob00677a.

Abstract

A simple and mild catalytic coupling reaction of propargyl halides with organotitanium reagents is reported. The reaction of propargyl bromide with organo-titanium reagents mediated by NiCl2 (2 mol%) and PCy3 (4 mol%) in CH2Cl2 afforded coupling product allenes in good to excellent yields (up to 95%) at room temperature. However, NiCl2(PPh3)2 was the best catalyst for substituted propargyl halides to yield allenes or alkynes preferentially. On the basis of the experimental results, a possible catalytic cycle has been proposed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkenes / chemical synthesis
  • Alkynes / chemical synthesis
  • Catalysis
  • Nickel / chemistry*
  • Organometallic Compounds / chemistry*
  • Pargyline / analogs & derivatives*
  • Pargyline / chemistry
  • Temperature
  • Titanium / chemistry*

Substances

  • Alkenes
  • Alkynes
  • Organometallic Compounds
  • Nickel
  • Pargyline
  • Titanium
  • propargyl bromide