Facile Ar-CF3 bond formation at Pd. Strikingly different outcomes of reductive elimination from [(Ph3P)2Pd(CF3)Ph] and [(Xantphos)Pd(CF3)Ph]

J Am Chem Soc. 2006 Oct 4;128(39):12644-5. doi: 10.1021/ja064935c.

Abstract

Facile and highly selective perfluoroalkyl-aryl reductive elimination from a metal center (Pd) has been demonstrated for the first time. At temperatures as low as 50-80 degrees C, [(Xantphos)Pd(Ph)CF3] undergoes remarkably clean decomposition to produce CF3Ph in high yield and selectivity. In contrast, analogous trifluoromethylpalladium aryls stabilized by rigid cis-chelating ligands such as dppe are completely unreactive at temperatures up to 130-140 degrees C. Decomposition of [(Ph3P)2Pd(Ph)CF3] in the presence of PhI in benzene at 60 degrees C does not produce PhCF3 but rather leads to [(Ph3P)2Pd(Ph)I] and [Ph4P]+[(Ph3P)Pd(CF3)3]- in a 2:1 ratio with high selectivity.

MeSH terms

  • Crystallography, X-Ray
  • Hydrocarbons, Fluorinated / chemical synthesis
  • Hydrocarbons, Fluorinated / chemistry*
  • Organometallic Compounds / chemical synthesis
  • Organometallic Compounds / chemistry*
  • Palladium / chemistry*
  • Phosphines / chemical synthesis
  • Phosphines / chemistry*
  • Xanthenes / chemistry*

Substances

  • Hydrocarbons, Fluorinated
  • Organometallic Compounds
  • Phosphines
  • Xanthenes
  • Palladium
  • xantphos