Why furan undergoes electrophilic substitution at C2 position and not at C3 position?

Answer and Explanation: The furan undergoes electrophilic substitution on the 2nd position. The electrophilic substitution at C2 position gives more resonating structures than substitution at C3 position. More the resonating structure, the molecule is more stable, so the C2 attack prefers.

Why does electrophilic substitution in pyrrole furan and thiophene primarily takes place at C 2-position?

Pyrrole, thiophene, and furan gives electrophilic aromatic substitution reaction. These compounds are more reactive compared to benzene. That’s why the attack of electrophiles takes place at 2nd position in pyrrole, thiophene, and furan.

Why pyrrole is more reactive than furan towards electrophilic substitution?

The electron density in the aromatic ring of furan is lesser than that of pyrrole. This is because of the electronegativity of the heteroatom (N and O). O is more electronegative than N, hence it withdraws electron density to itself more, leaving lower electron density in the ring itself.

Which position of pyrrole is more reactive towards electrophilic?

2-Position of pyrrole is more reactive towards electrophilic substitution than 3-position.

Why thiophene is less reactive than pyrrole and furan?

Oxygen attracts its electrons more strongly than sulfur, so delocalization in thiophene is more prominent. Therefore, aromatic stabilization is stronger in thiophene which makes it less reactive than furan.

Why is pyrrole more stable than furan?

Since N is less electronegative than O, it will be slightly more stable than O with that positive charge. Hence, pyrrole will be more aromatic than furan.

Why electrophilic substitution in pyrrole occurs at c2 and c3?

The difference is fairly clear: electrophilic aromatic substitution (EAS) occurring at carbon-2 gives one more resonance structure than on carbon-3, so that intermediate is more stable. Thus, EAS more readily occurs on carbon-2 starting with pure pyrrole.

What is the electrophilic substitution for C-2 in furan?

The electrophilic substitution at C-2 in furan and thiophene can also be accounted in the same manner. Furan is not as reactive as pyrrole in electrophilic substitution reactions because the oxygen in furan is more electronegative than nitrogen in pyrrole and therefore does not enhance the electron density of carbons as much as pyrrole.

Why is pyrrole more reactive for electrophilic substitution at C-2 and C-5 postions?

This is due to attack at C-2 gives more stable intermediate ( it is stabilised by three resonance structures ) than the intermediate resulted from C-3 attack (as it is stabilised by two resonance structures) Thus pyrrole is more reactive for electrophilic substitution at C-2 and C-5 postions.

What is the reactivity order of pyrrole furan and thiophene?

Reactivity order of Pyrrole, Furan and Thiophene towards Electrophilic substitution : Pyrrole, furan and thiophene undergo electrophilic substitution reactions like nitration, sulphonation, halogenation etc. characteristic of aromatic rings.

Is pyrrole electrophilic or aromatic?

Electrophilic Substitution in Pyrrole (Reactivity and Orientation) Pyrrole, thiophene, and furan gives electrophilic aromatic substitution reaction. These compounds are more reactive compared to benzene.