Following the initial report by Arduengo et al. in 1991, stable N-heterocyclic carbenes (NHCs) became a focus of organic chemists as organocatalysts and ligands, owing to their strong donor properties and easily modified, versatile structures.[1] NHCs are now recognized as efficient tools for organocatalysis and have become a fruitful area of research in synthetic organic chemistry.[2] In organocatalysis, the benzoin reaction is one of the ...