Skip to main content
Chemistry LibreTexts

Activating Group

If electrophilic aromatic substitution of a monosubstituted benzene is faster than that of benzene under identical conditions, the substituent in the monosubstituted benzene is called an activating group.





Under identical conditions, Reaction 2 is faster than Reaction 1.  Thus, the methyl group is an activating group.

All activating groups are electron-donating groups.

Common activating groups: