Addition-Elimination Mechanism

Area of ​​Expertise - Organic chemistry

The addition-elimination mechanism describes a reaction that occurs mainly in electrophilic aromatic substitution (Ar-SE.) and second-order nucleophilic substitution ($S.N2$) occurs. First the intervening nucleophile (Nu), or electrophile, enters the molecule with the formation of an intermediate product (addition). The intermediate products formed are stabilized again after the leaving group has been split off (X; elimination).

See also: addition, elimination

Learning units in which the term is dealt with

Aromatic reactions (total)90 min.

ChemistryOrganic chemistryAromatic chemistry

This learning unit begins with a description of the mechanism of electrophilic aromatic substitution, including energetic considerations of the intermediates and transition states. Furthermore, the dependencies between inductive and mesomeric effects and the reactivity and the secondary substitution of substituted aromatics are dealt with. The most important reactions are also presented. Finally, the less important nucleophilic aromatic substitution is explained, including the mechanism, intermediate stages, transition states, etc., etc. The conclusion is a description of the "production" and structure of arynes.

Aromatic reactions - Ar-SE - basics and theory30 min.

ChemistryOrganic chemistryAromatic chemistry

This learning unit begins with a description of the mechanism of electrophilic aromatic substitution, including energetic considerations of the intermediate and transition states. Furthermore, the dependencies between inductive and mesomeric effects and the reactivity of the second substitution of substituted aromatics are dealt with.