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Reactions of Pyrrole, Furan, and Thiophene definitions

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  • Pyrrole
    A five-membered aromatic ring containing nitrogen as the heteroatom, highly reactive in EAS due to lone pair stabilization.
  • Furan
    A five-membered aromatic ring with oxygen as the heteroatom, showing intermediate reactivity in EAS among the three compounds.
  • Thiophene
    A five-membered aromatic ring with sulfur as the heteroatom, less reactive in EAS compared to pyrrole and furan.
  • Heteroatom
    An atom other than carbon in a ring, such as nitrogen, oxygen, or sulfur, which stabilizes positive charge during EAS.
  • Electrophilic Aromatic Substitution
    A reaction where an electrophile replaces a hydrogen on an aromatic ring, restoring aromaticity after substitution.
  • Aromaticity
    A property of cyclic, planar molecules with delocalized pi electrons, providing extra stability to the ring.
  • Resonance Structure
    A different arrangement of electrons in a molecule, used to show charge delocalization and stabilization during reactions.
  • Regioselectivity
    A preference for a chemical reaction to occur at a specific position on a molecule, such as carbon 2 in these rings.
  • Pi Bond
    A bond formed by sideways overlap of p orbitals, involved in delocalization and reactivity in aromatic rings.
  • Electrophile
    A species attracted to electron-rich regions, accepting electrons from the aromatic ring during substitution.
  • Hydrogen Loss
    The step in EAS where a hydrogen atom is removed from the ring, allowing restoration of aromaticity.
  • Minor Product
    A less favored outcome in a reaction, such as substitution at carbon 3 in these heterocycles.
  • Major Product
    The predominant outcome in a reaction, such as substitution at carbon 2 in pyrrole, furan, and thiophene.
  • Reactivity Order
    The sequence of how readily compounds undergo EAS: pyrrole > furan > thiophene.
  • Lone Pair
    A pair of valence electrons not involved in bonding, often found on heteroatoms and crucial for resonance stabilization.