Table of Contents
- 1 Why is furan less reactive than pyrrole towards electrophilic substitution reaction?
- 2 Which of thiophene and furan is more reactive to Electrophile?
- 3 Why is furan more reactive than thiophene?
- 4 Why is pyrrole more reactive?
- 5 Is furan more reactive than pyrrole for electrophilic substitution reactions?
- 6 What is the difference between pyridine and pyrrole?
Why is furan less reactive than pyrrole towards electrophilic substitution reaction?
The lower reactivity of furan than pyrrole is because the oxygen atom accommodates positive charge less readily than the nitrogen atom, while the higher reactivity of furan than thiophene can be attributed to the smaller orientation effect (+M effect) of sulfur than that of oxygen.
What is the order of reactivity of pyrrole furan and thiophene towards Electrophiles?
The aromatic five-membered heterocycles all undergo electrophilic substitution, with a general reactivity order: pyrrole >> furan > thiophene > benzene.
Which position of pyrrole is more reactive towards electrophilic?
2-Position of pyrrole is more reactive towards electrophilic substitution than 3-position.
Which of thiophene and furan is more reactive to Electrophile?
Pyrrole
Pyrrole is more reactive than furan and thiophene in electrophilic reactions. 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 thiophene is more stable than pyrrole and furan?
Answer: 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 furan is less aromatic than pyrrole and thiophene?
The oxygen atom in furan, being slightly more electronegetive than nitrogen, holds the electrons to itself more closely than nitrogen does in pyrrole thus furan is less aromatic than pyrrole. The delocalization of electrons in furan is not as strong as that in pyrrole.
Why is furan more reactive than thiophene?
Originally Answered: Why is furan more reactive than thiophene towards electrophiles? This is because of the better delocalisation offered by oxygen ( due to better 2p-2p pi bonding with carbon ) which is relatively low in Sulphur ( 2p-3p pi bonding ). As delocalisation is better, the ring becomes more nucleophilic.
Why thiophene is more stable than furan and pyrrole?
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 furan undergoes electrophilic substitution at 2ndposition explain using the resonating structures?
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 is pyrrole more reactive?
Pyrrole is more reactive than pyridine for electrophilic substitution reactions because of the stability of the protonated pyrrole intermediate. Pyridine is more stable in its unreacted state compare to pyrrole due to its aromatic nature.
Why thiophene is more aromatic than pyrrole and pyrrole is more aromatic than furan?
That said, every resonating structure (except the uncharged one) for pyrrole and furan will create a formal positive charge on the hetero-atom. 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 is pyrrole more stable than furan?
Is furan more reactive than pyrrole for electrophilic substitution reactions?
I do not think that furan is more reactive than pyrrole for electrophilic substitution reactions. Reactivity in this case depends on how readily an electrophile attacks the compound. Hence a compound with higher electron density will be more susceptible to attack by electrophiles.
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.
Where does the attack of electrophiles take place in pyrrole?
That’s why the attack of electrophiles takes place at 2 nd position in pyrrole, thiophene, and furan.
What is the difference between pyridine and pyrrole?
Pyridine is a $\\pi$-deficient heterocycle owing to nitrogen’s more electronegative nature than carbon. Pyrrole on the other hand is $\\pi$ excessive since nitrogen donates its lone pair to the ring. The non-delocalized lone pair on pyridine tends to interact with the electrophile/$\\ce{H+}$.