An aromatic electrophilic substitution reaction is a chemical reaction in which the aromatic ring has a planar structure with a closed conjugation. It has pi-electrons which are mobile. When the electrophile approaches the aromatic ring, the electrons are displaced. The structure gets charged due to electromeric/mesomeric effect. This leads to the formation of a pi-complex. Formation of a complex is followed by the formation of Sigma Complex. The Sigma Complex is stable due to resonance taking place.

The Attacking Groups can be classified as:

  1. Activating Groups