When pyrrole undergoes electrophilic aromatic substitution, at which position does substitution occur?

When pyrrole undergoes electrophilic aromatic substitution, the substitution typically occurs at the C2 position. Pyrrole is a five-membered heterocyclic aromatic compound with four carbon atoms and one nitrogen atom. The electron density in the pyrrole ring is highest at the C2 position due to the presence of the nitrogen lone pair, making it more susceptible to electrophilic attack.

In electrophilic aromatic substitution reactions, an electrophile reacts with an aromatic ring, replacing one of the hydrogen atoms. The electrophile is attracted to the electron-rich region of the ring, which is usually the position that stabilizes positive charge or partial positive charge. In the case of pyrrole, the C2 position is the most nucleophilic and therefore the site of electrophilic substitution.