Heterocyclic Carbenes

摘要

About 30 years elapsed between the proposal of stable N-heterocyclic carbenes (NHCs) and the preparation of the first member of this class of compounds by Arduengo et al. The isolation of the stable imidazolin-2-ylidene 1 and the saturated imidazolidin-2-ylidene derivative 2 sparked renewed interest in the chemistry of N-heterocyclic carbenes and their metal complexes. Initially, the triazole derivative 3 and the benzannulated carbene 4 were prepared, both containing a diamine-stabilized carbene center as part of a five-membered ring.