Electrophilic and Nucleophilic Aromatic Substitution

The video tutorial covers electrophilic and nucleophilic aromatic substitution reactions, focusing on heterocyclic compounds like pyrrole, furan, and thiophene. It explains the reactivity order of these compounds compared to benzene and the preferred positions for electrophilic attack. The tutorial also delves into the mechanisms of these reactions, highlighting the role of resonance and the octet rule in determining stability. Additionally, it discusses nucleophilic aromatic substitution, emphasizing the importance of leaving group positions and the conditions required for these reactions.

Why does bromination of pyrrole not require a Lewis acid catalyst?

• Pyrrole is less reactive than benzene.

• Pyrrole is not an aromatic compound.

• Pyrrole is more nucleophilic than benzene.

• Bromine is a weak electrophile.

Which position does bromine prefer to substitute in pyrrole?

• Position 4

• Position 3

• Position 2

• Position 1

Which of the following is more nucleophilic than benzene?

• Furan

• All of the above

• Thiophene

• Pyrrole

Why is thiophene less nucleophilic than furan?

• Furan has a larger ring size.

• Thiophene is not aromatic.

• Sulfur's 3p orbital does not overlap effectively with carbon's 2p orbital.

• Sulfur is more electronegative than oxygen.

Why does electrophilic attack prefer the two position in pyrrole?

• It allows for more resonance structures.

• It is less sterically hindered.

• It is closer to the nitrogen atom.

• It is more electronegative.

In pyridine, which position is favored for electrophilic substitution?

• Position 2

• Position 3

• Position 1

• Position 4

Why is pyridine less reactive than benzene in electrophilic aromatic substitution?

• Pyridine is not aromatic.

• Pyridine has a nitrogen atom that deactivates the ring.

• Pyridine is more nucleophilic.

• Pyridine has a larger ring size.

What is required for nucleophilic aromatic substitution in pyridine?

• A leaving group at position 5

• A catalyst

• A strong nucleophile

• A leaving group at position 3

Which position in pyridine is not favorable for nucleophilic aromatic substitution?

• Position 2

• Position 4

• Position 3

• Position 1

Why are hydrogen atoms on methyl groups in pyridine relatively acidic?

• They are adjacent to a nitrogen atom.

• They are bonded to a carbon atom.

• They are stabilized by resonance.

• They are part of an aromatic ring.