Imidazol‐2‐ylidene Reactivity towards Cyanocarbons

The interaction of electron rich imidazol-2-ylidenes with electron poor cyanocarbons is reported. Contrary to previous reports of electron transfer products from imidazol-2-ylidenes and tetracyanoethylene, a number of ring forming cyanocarbon ring structures are isolated and characterized. Cyanation of the imidazole ring was explored by the addition of cyanogen chloride to imidazol-2-ylidenes. Backbone cyanation often occurs when hydrogen atoms are in the C-4/5 positions. When tetrasubstituted imidazol-2-ylidenes are employed, 2-cyanoimidazolium halide salts can be isolated. These salts maintain an electrophilic cyano group and are precursors to thermally stable high nitrogen content imidazolium tetrazolides.