Carbonsäureamiden

Carbonsäureamiden, often simply referred to as amides, are organic compounds derived from carboxylic acids by replacing the hydroxyl group with an amino group. The general formula for amides is R-CO-NR'R'', where R, R', and R'' can be hydrogen atoms or alkyl or aryl groups. The functional group -CO-N< is characteristic of amides.

Amides are classified based on the number of organic groups attached to the nitrogen atom. Primary amides have two hydrogen atoms on the nitrogen (R-CO-NH2), secondary amides have one organic group and one hydrogen atom (R-CO-NHR'), and tertiary amides have two organic groups on the nitrogen (R-CO-NR'R'').

The carbon atom of the carbonyl group (C=O) in amides is electrophilic, while the nitrogen atom is nucleophilic due to the lone pair of electrons. However, the resonance interaction between the nitrogen's lone pair and the carbonyl pi system reduces the electrophilicity of the carbonyl carbon and the basicity of the nitrogen compared to amines. This resonance also leads to a partial double bond character in the carbon-nitrogen bond, restricting rotation.

Amides are important in biological systems, most notably as the peptide bond that links amino acids to form proteins. They are generally less reactive than other carboxylic acid derivatives like acid halides or anhydrides. Amides can be hydrolyzed in the presence of acids or bases to yield the corresponding carboxylic acid and amine.