Carbanion

As a carbanion (read carbanion ) is a negatively charged carbon atom to which usually, one or more electron-withdrawing substituents ( carbonyl aldehydes, esters or ketones as well as a nitrile residue, etc.) are bonded referred to in the organic chemistry.

In contrast to the primary carbenium ion carbanions are more stable than secondary carbanions and these stable than tertiary carbanions.

The chemical behavior of Grignard reagents ( RMgBr or RMgCl ), and alkyllithiums ( RLi ) corresponding to a negatively-charged alkyl group ( R ) of a carbanion. Isonitriles ( R NC) as well as reacting carbanion, for example, the Passerini reaction, or the Ugi reaction.

Carbanions often occur as reactive intermediates, which are often stabilized by resonance. Examples:

• Claisen condensation
• Knoevenagel reaction
• Dieckmann cyclization
• Enolates