Chapter 12 :Reactions of Arenes. Electrophilic Aromatic Substitution

The structure and properties of aromatic systems were discussed in Chapter 11.  Now it is time to visit their chemical reactions.
The arene system contains an electron rich C=C system which react with electrophiles via a substitution pathway (to preserve aromaticity) via what is known as electrophilic aromatic substitution (EArS):

• An electrophile, E⁺, is an electron poor species that will react with an electron rich species (the arene)
• Aromatic because the reaction is characteristic of aromatic systems.
• A substitution implies that a group is replaced (usually H).

Electrophilic Aromatic Substitution reactions

• Overview
• Table of EArS reactions and reagents
• Nitration
• Sulfonation
• Halogenation
• Friedel-Crafts alkylation
• Friedel-Crafts acylation
• Limitations of Friedel-Crafts reactions
• Substituent Effects -  (table of substituent effects)
  
• Making polysubstituted benzenes
• Polyaromatics
• Heterocycles

• Sample problems
• More practice problems ?
• Reaction Drills

© Dr. Ian Hunt, Department of Chemistry, University of Calgary