From Anionic N-HeterocyclicDicarbenes to AbnormalCarbene–Borane Complexes: A Logical Synthetic Route.

The anionic N-heterocyclic dicarbenes (NHDCs) Iaredemonstrated to be a convenient platform from which abnormal NHC (aNHC)–borane complexes V–VIImay be prepared. The anionic NHDC binuclear complex IIand the aNHC mononuclear adduct VIIcan be interconverted through lithiation and protonation,respectively, of the C2 carbon atom of the imidazole ring. [ABSTRACT FROM AUTHOR]