REACTIONS OF AROMATIC COMPOUNDS
Substituents Can Affect Both the Reactivity of the Ring and the Orientation of the Incoming Group
Electron-Donating and Electron-Withdrawing Substituents
Whether a substituent is an activating group or a deactivating group, and whether it is an ortho–para director or a meta director, depends largely on whether the substituent donates electrons to the ring or whether it withdraws electrons.
- All electron-donating groups are activating groups and all are ortho–para directors.
- With the exception of halogen substituents, all electron-withdrawing groups are deactivating groups and all are meta directors.
- Halogen substituents are weakly deactivating groups and are ortho–para directors.
Next Topic:- Groups: Ortho–Para Directors