Substitution reaction mechanism || Electrophilic Substitution Reaction In Benzene

Electrophilic Substitution Reaction: There are following steps are involved in the mechanism

  • Step 1: Generation of an electrophile (𝐄+)
  • Step 2: Formation of the carbocation intermediate
  • Step 3: Loss of proton from carbocation intermediate

Why Benzene gives Substitution Reaction rather than Addition || Oxidation || Polymerization In this video we explained the following points: Substitution reaction mechanism

  • 1: It gives Electrophilic substitution reactions
  • 2: Do not give Nucleophilic substitution reactions
  • 3: Do not undergo an oxidation reaction
  • 4: Do not undergo addition reaction
  • 5: Do not undergo a polymerization reaction

5 types of Electrophilic Substitution Reactions of benzene.

  • 1: Halogenation
  • 2: Nitration
  • 3: Sulphonation
  • 4: Friedel-Crafts alkylation
  • 5: Friedel-Crafts acylation

Aromatic Substitution Reaction

Aromatic electrophilic substitution reactions SEAr and aromatic nucleophilic substitution reactions SNAr (S stands for substitution, N stands for nucleophilic, Ar stands for aromatic), Ar stands for aryl. 

Aromatics can introduce nitro, halogen, sulfonic and alkyl or acyl groups on the aromatic ring through nitration, halogenation, sulfonation, and alkylation or acylation reactions, all of which are SEAr. For compounds that have substituents on the aromatic ring, the substituent has a positioning effect on the attack of the reagent. 

When the substituent on the benzene ring is an electron-donating group and a halogen atom, the electrophile enters its ortho and para positions more, when a substituent is an electron-withdrawing group, the meta product is mainly obtained. 

Sanjay Bhandari

Hello Friends, My name is Sanjay Bhandari. I am a chemistry Teacher.

Leave a Reply