Table of contents

1. A Review of General Chemistry5h 5m
2. Molecular Representations1h 14m
3. Acids and Bases2h 46m
4. Alkanes and Cycloalkanes4h 17m
5. Chirality3h 39m
6. Thermodynamics and Kinetics1h 22m
7. Substitution Reactions1h 48m
8. Elimination Reactions2h 30m
9. Alkenes and Alkynes2h 9m
10. Addition Reactions3h 19m
11. Radical Reactions1h 58m
12. Alcohols, Ethers, Epoxides and Thiols2h 42m
13. Alcohols and Carbonyl Compounds2h 17m
14. Synthetic Techniques1h 26m
15. Analytical Techniques:IR, NMR, Mass Spect7h 3m
16. Conjugated Systems6h 13m
17. Ultraviolet Spectroscopy51m
18. Aromaticity2h 34m
19. Reactions of Aromatics: EAS and Beyond5h 1m
20. Phenols55m
21. Aldehydes and Ketones: Nucleophilic Addition4h 56m
22. Carboxylic Acid Derivatives: NAS2h 51m
23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides1h 10m
24. Enolate Chemistry: Reactions at the Alpha-Carbon1h 53m
25. Condensation Chemistry2h 9m
26. Amines1h 43m
27. Heterocycles2h 0m
28. Carbohydrates5h 53m
29. Amino Acids4h 20m
30. Peptides and Proteins2h 42m
31. Catalysis in Organic Reactions1h 30m
32. Lipids 2h 50m
33. The Organic Chemistry of Metabolic Pathways2h 52m
34. Nucleic Acids1h 32m
35. Transition Metals6h 14m
36. Synthetic Polymers1h 49m

8. Elimination Reactions

Nucleophiles and Basicity

Organic Chemistry

8. Elimination Reactions

Nucleophiles and Basicity

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3:30 minutes

Problem 10

Textbook Question

Between pyrrole and pyrrolidine, which nitrogen would be most nucleophilic? Why?

Verified step by step guidance

Understand the structures of pyrrole and pyrrolidine: Pyrrole is a five-membered aromatic ring containing one nitrogen atom, while pyrrolidine is a five-membered saturated ring (non-aromatic) containing one nitrogen atom.

Analyze the electronic environment of the nitrogen in pyrrole: In pyrrole, the nitrogen's lone pair is delocalized into the aromatic π-system, contributing to the aromaticity of the ring. This delocalization reduces the availability of the lone pair for nucleophilic attack.

Analyze the electronic environment of the nitrogen in pyrrolidine: In pyrrolidine, the nitrogen is sp³ hybridized, and its lone pair is localized (not involved in any delocalization or aromaticity). This makes the lone pair more available for nucleophilic attack.

Compare the nucleophilicity of the two nitrogens: Nucleophilicity depends on the availability of the lone pair to donate electrons. Since the lone pair on the nitrogen in pyrrolidine is localized and not involved in aromaticity, it is more nucleophilic than the nitrogen in pyrrole.

Conclude: The nitrogen in pyrrolidine is more nucleophilic than the nitrogen in pyrrole because its lone pair is not delocalized and is more readily available for nucleophilic interactions.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Nucleophilicity

Nucleophilicity refers to the ability of a species to donate an electron pair to an electrophile during a chemical reaction. It is influenced by factors such as charge, electronegativity, and steric hindrance. A stronger nucleophile is typically more reactive and can more readily form bonds with electrophiles.

Aromaticity

Aromaticity is a property of cyclic compounds that exhibit resonance stability due to the delocalization of π electrons. Pyrrole, which contains a nitrogen atom in its ring, is aromatic and has a stable electron cloud, which affects the reactivity of its nitrogen atom compared to non-aromatic compounds like pyrrolidine.

Basicity of Nitrogen

The basicity of nitrogen in organic compounds is determined by its ability to accept protons (H+). In pyrrole, the nitrogen's lone pair is involved in the aromatic system, making it less available for protonation and nucleophilic attack. In contrast, pyrrolidine has a more available lone pair, making its nitrogen more basic and nucleophilic.

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