Iron and Cobalt Metallotropism in Remote‐Substituted NHC Ligands: Metalation to Abnormal NHC Complexes or NHC Ring Opening. (19th September 2018)

• Record Type: Journal Article
• Authors: Danopoulos, Andreas A.; Massard, Alexandre; Frison, Gilles; Braunstein, Pierre
• Is Part Of: Angewandte Chemie. Volume 130:Number 44(2018)
• Page Start: 14758
• Page End: 14762
• Publication Date: 2018-09-19
• Subjects: Cobalt -- Eisen -- Metallotropie -- N-heterocyclische Carbene -- Zweikernkomplexe; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201808008
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Metallotropism of the M[N(SiMe3 )2 ]2 metal fragment in the tautomeric systemIA R ⇌AC R involving imidazolium salts/N‐heterocyclic carbenes with remote aminide/amine substituents, respectively, is manifested by its CNHC carbophilicity (R=tBu, M=Co, Fe) or NRaminido nitrogenophilicity (R=Cy, M=Co, Fe; R=Mes, M=Fe) and has been rationalized on the basis of steric and electronic effects. The thermolysis products of the [M{N(SiMe3 )2 }2 ]/IA R ⇌AC R system are also substituent‐dependent, leading to a rearranged aminide‐functionalized aNHC Co2 complex of an unprecedented type or to ring‐opened metallaketenimines; they are postulated to originate from different metalloisomers. The results are interpreted on the basis of the X‐ray diffraction analysis of 11 new compounds.