Carbimide

Carbimide is a term that can refer to a few related chemical concepts. Most commonly, it is used as a prefix to describe a functional group containing a carbon atom double-bonded to a nitrogen atom and single-bonded to another nitrogen atom, with a net formal charge of zero. This structure, R2N-N=C=NR2, is a type of carbodiimide. Carbodiimides are a class of organic compounds with the general formula R-N=C=N-R. They are known for their reactivity, particularly as coupling agents in organic synthesis, facilitating the formation of amide and ester bonds.

In some contexts, carbimide might also refer to a hypothetical compound or intermediate involving a carbon-nitrogen double bond with some specific bonding arrangement. However, the carbodiimide interpretation is the most prevalent in chemical literature. The reactivity of carbodiimides stems from the polarized nature of the N=C double bond and the presence of the central cumulative double bond system. They react readily with nucleophiles such as alcohols, amines, and carboxylic acids.

The synthesis of carbodiimides often involves the dehydration of ureas or thioureas. Due to their utility in forming peptide bonds and other crucial linkages, carbodiimides like dicyclohexylcarbodiimide (DCC) and N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC·HCl) are widely employed in biochemical research and the pharmaceutical industry.