Electrophilic Aromatic Substitution?

📌 CONCEPT: Electrophilic Aromatic Substitution is a type of organic reaction where an electrophile replaces a hydrogen atom in an aromatic ring.

📐 RULE / FORMULA: The reaction follows the general mechanism: E+ (Electrophile) + ArH (Aromatic Compound) → EArH (E-substituted Aromatic Compound) + H+.

💡 WORKED EXAMPLE: Consider the reaction of bromine with benzene: Br2 (Electrophile) + C6H6 (Benzene) → C6H5Br (Bromobenzene) + HBr. In this example, bromine acts as an electrophile, replacing a hydrogen atom in the benzene ring. The reaction occurs in the presence of light, which provides the necessary energy for the reaction to proceed.

⚠️ COMMON MISTAKE: Students often get confused between Electrophilic Aromatic Substitution and Nucleophilic Aromatic Substitution. They should note that in Electrophilic Aromatic Substitution, the electrophile replaces a hydrogen atom, whereas in Nucleophilic Aromatic Substitution, a nucleophile replaces a substituent group.