Textbook Question
What products would you expect from the following coupling reactions?
(d)
(e)
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19. Reactions of Aromatics: EAS and Beyond
Benzene Reactions
Multiple Choice
Which type of substituent on a benzene ring increases the rate of electrophilic aromatic substitution (EAS) reactions by activating the ring toward electrophiles?
A
Alkyl groups always deactivate the benzene ring toward EAS reactions
B
Electron-withdrawing groups such as or
C
Electron-donating groups such as or
D
Halogen substituents such as or
Verified step by step guidance1
Understand that electrophilic aromatic substitution (EAS) reactions involve an electrophile attacking the electron-rich aromatic ring.
Recognize that substituents on the benzene ring influence the electron density of the ring, thereby affecting its reactivity toward electrophiles.
Electron-donating groups (EDGs), such as hydroxyl (\$\(\mathrm{OH}\)\$) and methoxy (\$\(\mathrm{OCH_3}\)\$), increase the electron density on the ring through resonance or inductive effects, activating the ring toward EAS.
In contrast, electron-withdrawing groups (EWGs), like nitro (\$\(\mathrm{NO_2}\)\$) or carboxyl (\$\(\mathrm{COOH}\)\$), decrease electron density, deactivating the ring and slowing EAS reactions.
Halogen substituents (e.g., \$\(\mathrm{Cl}\)\$, \$\(\mathrm{Br}\)\$) are unique because they are deactivating due to their electronegativity but can direct substitution to ortho/para positions due to resonance donation.
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