Electrophilic Reactivity is the tendency of aromatic or unsaturated compounds to undergo reactions with electron-seeking species (electrophiles).
Reactivity toward EAS depends on electron density in the ring. More electron-rich rings react more easily.
Advertisements
Comparison of EAS Reactivity
| Compound | Electron Density | Reactivity toward EAS | Preferred Position of Attack |
| Pyrrole | Highest | Most reactive | Position-2 (α) |
| Furan | Moderate | Intermediate | Position-2 (α) |
| Thiophene | Lowest (still high vs. benzene) | Least reactive among the three | Position-2 (α) |
Why?
-
- Pyrrole’s nitrogen donates electron density strongly → makes ring highly nucleophilic
- Furan’s oxygen is more electronegative → reduces overall electron density
- Thiophene is more stable and aromatic, making it less eager to undergo substitution
- Thus, electrophilic reactivity decreases in the order:
-
- Pyrrole > Furan > Thiophene
-
- Note: All three are more reactive than benzene in EAS reactions.
Thank you for reading from Firsthope's notes, don't forget to check YouTube videos!
Advertisements
Advertisements
