1. Reaction with electrophiles - Protonation
PYRROLES
Reaction with electrophiles - Protonation
Protonated pyrroles ≈ iminium ions
Reactive intermediates in many react.

2. Reaction with electrophiles - E-fil Ar. Subst.
Nitration
Sulfonation
Halogenation
FC-acylation
(FC-alkylation)

3. Reaction with electrophiles - E-fil Ar. Subst.
-Halogenation
Haloindoles (esp. 2-halo-) unstable

4. Reaction with electrophiles - E-fil Ar. Subst.
-Acylation

5. Reaction with electrophiles - E-fil Ar. Subst.
-Alkylation
Low reactivity,
unselective,
polymerization etc

6. Reaction with electrophiles - Condensation with aldehydes / ketones
2:1 adducts
With electron rich arylaldehydes
Indoles

7. Vit. B12 Application in Porphyrine Synthesis Hemoglobine Myoglobine
Cytochromes

8. Application in Porphyrine Synthesis

9. Reaction with electrophiles - Condensation with Imines / Iminum Ions
Pyrrole punstable in acidic media

10. Reaction with electrophiles - Condensation with Imines / Iminum Ions
Mannich react.
Vilsmeier react. (Vilsmeier-Haack): Formylation

11. Reaction with nucleophiles
Electron rich ring - not very reactive towards Nu
Indole: React. In benzene ring prefered
Reaction with base and further react. with E-files
N-alkylation favoured by:
Ionic N-Met bond (Li)
High solvating power of solvent
(DMF, DMSO etc., crown ethers, PTC)

12. C-metallation and further react.
Simple routes to 2- or 3-subst. indoles
Electrophilic Palladation

13. Radical Reactions

14. Cyclo Additions Pyrrole as diene (4 component) Vinylpyrrole as diene
EWG: Less interact. Between Lone pair on N
and “diene”
Vinylpyrrole as diene
Pyrrole as dienophile (2 component)
A few intramolek. ex.

15. Cyclo Additions Indole as diene (4 component) Vinylindole as diene
No examples
Vinylindole as diene
Indole as dienophile (2 component)

16. Reaction with carbenes / carbenoids
Indoles: No cyclopropanes isolated from carben(oid) react.
Pyrrole / Indole Carboxylic Acids
Also decarboxylation of indole carboxylic acids

17. Oxypyrroles
Oxyindoles

18. Aminopyrroles Aminoindoles -Amino (not iminoform) - unstable
3-Amino - unstable

19. Azaindoles (Pyrrolopyridines)
5-membered ring≈ pyrrol (less electron rich)
6-membered ring≈pyridine (more electron rich)