Friedel-Crafts alkylation is generally an unsuccessful method for introducing an alkyl group onto wh — Aromatic Hydrocarbons Chemistry Question

💡 Solution & Explanation

Friedel-Crafts reactions (both alkylation and acylation) fail on aromatic rings bearing powerful electron-withdrawing groups (strong meta-directors). The $-NO_2$ group is highly deactivating, making the ring too electron-deficient to attack the electrophile. Additionally, basic groups like $-NH_2$ also fail because they complex with the Lewis acid catalyst, turning into powerful deactivators.