Aromatic compounds are rather unique hydrocarbons. While they are unsaturated in nature, they do not participate in any addition reactions typical for unsaturated hydrocarbons. Thus, reactions of aromatic compounds present a new rich collection of functional transformations and carbon chain modifications specific to this group of compounds. The typical reactions of aromatic compounds are:
–is a reaction between an aromatic compound and a halogen (typically Cl2 or Br2) catalyzed by a Lewis Acid. This is one the simplest yet highly valuable reaction of aromatic compounds.
–is a reaction that adds a side chain to an aromatic compound. The reaction often involves carbocationic rearrangements of the side chain and multiple alkylation reactions. Because of these disadvantages, the Friedel-Craft alkylation is not very useful for synthetic purposes.
–is a reaction that is mechanistically similar to the alkylation, however, due to the deactivating effect of the side chain, multiple alkylations are not observed.
–is a reaction between concentrated sulfuric acid (H2SO4) and an aromatic compound that produces aromatic sulfonic acids. The reaction is reversible, so the sulfo-group can serve as a temporary blocker for a multi-step synthesis purposes.
–is a similar reaction to the sulfonation. In this reaction a nitro-group is added to the molecule. Later, the nitro-group can be reduced to an aromatic amine.
–is a unique reaction of the aromatic compounds that results in a formation of non-conjugated 1,4-cyclohexadienes.
Nucleophilic Aromatic Substitution (Addition-Elimination)
–is a reaction in which a leaving group on an aromatic ring is substituted with a suitable nucleophile. The reaction has wide synthetic applications and is biochemically important.
Nucleophilic Aromatic Substitution (Elimination-Addition)
–is another version of the nucleophilic substitution in aromatic compounds. This reaction however, has a very limited applicability due to the lack of regioselectivity.
–is a reaction of a partial or a complete oxidation of a carbon-containing side chain of an aromatic compound. Reaction is useful in some synthetic procedures, however, it has a limited scope and applicability due to the harsh nature of the conditions.
Reactions of the Diazonium Salts
-is a family of reactions that give a way to convert the diazonium salt of an aromatic compound to a large range of functional groups.