Molecular Manipulations of a Utility Nitrogen–Heterocyclic Carbene by Sodium Magnesiate Complexes and Transmetallation Chemistry with Gold Complexes

Alberto Hernán-Gómez, Marina Uzelac, Sharon E. Baillie, David R. Armstrong, Alan R. Kennedy, M. Ángeles Fuentes, Eva Hevia

Research output: Contribution to journalArticlepeer-review

8 Citations (SciVal)

Abstract

Expanding the scope and applications of anionic N-heterocyclic carbenes (NHCs), a novel series of magnesium NHC complexes is reported using a mixed sodium–magnesium approach. Sequential reactivity of classical imidazol- 2-ylidene carbene IPr with NaR and MgR2 (R=CH2SiMe3) affords [(THF)3Na(μ-IPr)MgR2(THF)] (2) [IPr=:C{[N(2,6-iPr2C6H3)]2CHC] containing an anionic NHC ligand, whereas surprisingly sodium magnesiate [NaMgR3] fails to deprotonate IPr affording instead the redistribution coordination adduct [IPr2Na2MgR4] (1). Compound 2 undergoes selective C2-methylation when treated with MeOTf furnishing novel abnormal NHC complex [{aIPrMeMgR2}2] (3). Dissolving 3 in THF led to the dissociation of this complex into MgR2 and aIPrMe with the latter isomerizing to the olefinic NHC IPr=CH2. The ability of 2 and 3 to transfer their anionic and abnormal NHC ligands, respectively to AuI metal fragments has been investigated allowing the isolation and structural characterization of [RAu(μ-IPr)MgR(THF)2] (4) and [aIPrMeAuR] (5) respectively. In both cases transfer of an alkyl R group is observed. However while 3 can also transfer its abnormal NHC ligand to give 5, in 4 the anionic NHC still remains coordinated to Mg via its C4 position, whereas the {AuR} fragment occupies the C2 position previously filled by a donor-solvated {Na(THF)3}+ cation.

Original languageEnglish
Pages (from-to)10541-10549
Number of pages9
JournalChemistry - A European Journal
Volume24
Issue number41
DOIs
Publication statusPublished - 20 Jul 2018

Bibliographical note

Funding Information:
Funding is acknowledged from the European Research Council (ERC) MIXMETAPPS-279590 FP7 project. We thank Professor Robert E. Mulvey for his insightful comments and Mr Alexander Clunie for his assistance in the CHN analysis of highly air and moisture sensitive compounds.

Publisher Copyright:
© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Keywords

  • cooperative effects
  • gold
  • magnesium
  • mixed metal
  • N-heterocyclic carbenes

ASJC Scopus subject areas

  • Catalysis
  • Organic Chemistry

Fingerprint

Dive into the research topics of 'Molecular Manipulations of a Utility Nitrogen–Heterocyclic Carbene by Sodium Magnesiate Complexes and Transmetallation Chemistry with Gold Complexes'. Together they form a unique fingerprint.

Cite this