Moderate Activators

Moderate Activators Definition:

Groups that moderately activate an aromatic ring toward an electrophilic aromatic substitution reaction.

Moderate Activators Explained:

Activators are electron donating atoms or functional groups, and there is 3 type of activators: strong, moderate, and weak.

Activators are known to be ortho-para directors, and I would like to understand the reason behind that. There is a strong activator, and the reason of ortho-para major products is due to the fact that we have 4 resonance structures, whereas in the meta position we have only 3. When we have a weak activator, and the reason of ortho-para major products is the result of the fact that there is resonance structures, a positive charge of the sigma complex that is directly adjacent to the electron-donating alkyl group. Moderate is when we have both factors but in moderate conditions.