Friedel–Crafts Acylation: Installing Acyl Groups on Aromatic Rings

Learn Friedel–Crafts acylation step-by-step: acylium ion formation, sigma complex, and deprotonation. Understand why it avoids rearrangements and polyacylation and how it differs from alkylation.

  • Electrophile: Acylium ion (R–C≡O+ resonance-stabilized)
  • Reagents: RCOCl (or anhydride) + AlCl3
  • Key advantages: No rearrangements; usually monoacylation
  • Product: Aryl ketone
  • Exam type: Predict the major product
  • Exam type: Choose conditions
  • Exam type: Failure modes / distractors

Related Resources

All 194 Mechanisms — Aromatic & Pericyclic (High-Yield Orgo II) Mechanism Flashcards AI Reaction Predictor Ask the AI Tutor