page_title: Electrophilic aromatic directing groups
section_title: Directing effect on multiple substituents
hierarchical_section_title: Electrophilic aromatic directing groups / Directing effect on multiple substituents
caption_attribution_description: English: When different groups are attached to benzene, the 3rd substituent depends for the o/p director.
context_page_description: In an electrophilic aromatic substitution reaction, existing substituent groups on the aromatic ring influence the overall reaction rate or have a directing effect on positional isomer of the products that are formed. An electron donating group or electron releasing group is an atom or functional group that donates some of its electron density into a conjugated π system via resonance or inductive effects —called +M or +I effects, respectively—thus making the π system more nucleophilic. As a result of these electronic effects, an aromatic ring to which such a group is attached is more likely to participate in electrophilic substitution reaction. EDGs are therefore often known as activating groups, though steric effects can interfere with the reaction.
  An electron withdrawing group will have the opposite effect on the nucleophilicity of the ring. The EWG removes electron density from a π system, making it less reactive in this type of reaction, and therefore called deactivating groups.
  EDGs and EWGs also determine the positions on the aromatic ring where substitution reactions are most likely to take place; this property is therefore important in processes of organic synthesis.
context_section_description: When two substituents are already present on the ring, the third substituent's place will be on a located place. The rules for the substituent are as follows:
  When two ortho/para directors are meta to each other, the third substituent will not be located between them.
  When both an ortho/para director and a meta director is present on the ring, the third substituent's place depends on the ortho/para director.
  When both group are the same director, the third substituent depends on the stronger one.
  When both group have similar directing effect and are para to each other, the third substituent depends on the less hindered one.
caption: The arrow shows the major products
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