Functionalized N-heterocyclic carbene nonspectator ligands upon internal alkyne activation reactions

Inorg Chem. 2013 Jun 3;52(11):6502-9. doi: 10.1021/ic400433z. Epub 2013 May 10.

Abstract

When studying the activation of 3-arylpropiolates by [TpRu(picolyl-(R)I)Cl]/NaBAr(F)4 (picolyl-(Me)I = 3-methyl-1-(2-picolyl)imidazol-2-ylidene (1); picolyl-(Me)BI = 3-methyl-1-(2-picolyl)benzoimidazol-2-ylidene (2)) a migratory insertion of the NHC into a ruthenium-carbon bond and an unprecedented C-N bond activation of the chelating picolyl-NHC ligand take place to give the new ruthenium metallacycles [TpRu(κ(3)-C,N,N'-═C(Ph)-C(CH2Py)(CO2Me)((Me)I)][BAr(F)4] 3a and 4a and [TpRu(κ(3)-C,N,N'-═C(4-CF3Ph)-C(CH2Py)(CO2Me)((Me)I)][BAr(F)4] 3b and 4b. X-ray crystal structures of 3a and 3b are reported, and a mechanistic pathway is proposed. In contrast, activation of internal alkynones by a mixture of [TpRu(picolyl-(Me)I)Cl] complex (1) and NaBAr(F)4 led to isolation and characterization of the corresponding disubstituted vinylidene complexes. Also, structures of [TpRu(picolyl-(Me)I)(═CC(COR)(Ph)][BAr(F)4] (R = Me (6a); Ph (6b)) are reported.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkynes / chemistry*
  • Crystallography, X-Ray
  • Heterocyclic Compounds / chemistry*
  • Ligands
  • Methane / analogs & derivatives*
  • Methane / chemistry
  • Models, Molecular
  • Molecular Conformation
  • Organometallic Compounds / chemical synthesis
  • Organometallic Compounds / chemistry*
  • Ruthenium / chemistry*

Substances

  • Alkynes
  • Heterocyclic Compounds
  • Ligands
  • Organometallic Compounds
  • carbene
  • Ruthenium
  • Methane