Why is furan more reactive than benzene

Then, suppose we examine the intermediate where one "Br" has already attached on either carbon-2 or carbon-3 as follows:. 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. The mechanism is fairly simple; just get an electrophile, then pyrrole can slowly act as a nucleophile. Afterwards, it quickly restores its aromaticity.

Overall, the carbon position depends on the stability of the resonance structures for the intermediate that forms. In this case it worked out as carbon-2 for pure pyrrole. If both carbon-2 positions are occupied, then carbon-3 will be the reactive position.

Oxygen, being more electronegative than nitrogen, distributes more negative charge density upon itself and less upon the ring, thus stabilizing the carbocation intermediate less , making furan less reactive towards EAS than pyrrole.

And pyrrole, furan, and thiophene are all more reactive than benzene with EAS because the lone pair on the heteroatom can donate electron density into the ring by resonance, thus stabilizing the carbocation intermediate more effectively.

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Forum Organic Chemistry Why furan is more reactive than pyrrole and Why furan is more reactive than pyrrole and thiophene? Why the electrophilic attack at the alpha position in pyrrole is preferred? Estanislaa Astarbe Pundit. Why is pyridine electron deficient? Chemical properties. Marzouk Aranzibia Pundit. What is heterocyclic aromatic compounds?

Heterocyclic Aromatic Compounds. A heterocyclic compound is an organic compound in whichone or more of the carbon atoms in the backbone of the molecule hasbeen replaced by an atom other than carbon. Typical hetero atomsinclude nitrogen, oxygen, and sulfur. Geeta Elsperger Pundit. Why is pyridine more basic than imidazole? Imidazole is an aromatic ring found in manybiological molecules.

One of its nitrogen atoms resembles that ofpyrrole, and is not basic. However, imidazole isabout times more basic than pyridine. The increasedbasicity results from resonance stabilization of the positivecharge of the conjugate acid. Evangelica Keshavan Teacher.

Is pyridine activating or deactivating? Pyridine acts as an electron--withdrawing and deactivating substituent, and therefore directsmeta.

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