In electrophilic aromatic substitution, what kind of substituent is typically a meta-director?

• A. Electron-donating group
• B. Electron-withdrawing group
• C. Neutral group
• D. Sterically bulky group

Answer: (B)

Meta-directing behavior in electrophilic aromatic substitution comes from how substituents influence the stability of the arenium ion intermediate. Electrophilic attack creates a positively charged sigma complex on the ring. Electron-donating groups stabilize positive charge at the ortho and para positions by resonance, steering the reaction to those positions. Electron-withdrawing groups, on the other hand, destabilize those ortho/para intermediates and therefore reduce the likelihood of substitution there. At the meta position, the developing positive charge avoids being adjacent to the withdrawing group, making that route comparatively more stable. So, electron-withdrawing groups direct substitution to the meta position, even though they often deactivate the ring overall.