Synthesis of bis-NHC precursors and study of their coordination capabilities

Abstract

N-Heterocyclic carbenes (from now on NHCs) are neutral compounds containing a divalent carbon atom with six valence electrons and being part of a nitrogen atom containing heterocycle. Four electrons are involved in σ-bonds and the other two remain at the central carbon. Their incomplete electron octet and their coordinative unsaturation, render free carbenes unstable. Indeed, they were considered only as highly reactive transient intermediates for decades. [...]