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

21. Aldehydes and Ketones: Nucleophilic Addition

Imine vs Enamine

Organic Chemistry

21. Aldehydes and Ketones: Nucleophilic Addition

Imine vs Enamine

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4:59 minutes

Problem 22c,d

Textbook Question

Predict the products of the following reactions.
(c)
(d)

Verified step by step guidance

Step 1: Analyze the reaction in part (a). The reactants include a ketone (acetophenone) and an amine (aniline) in the presence of an acid catalyst (H⁺). This is a typical reaction for imine formation, where the carbonyl group reacts with the amine to form a C=N bond.

Step 2: In part (a), the mechanism begins with the protonation of the carbonyl oxygen by H⁺, increasing the electrophilicity of the carbonyl carbon. The amine (PhNH₂) then attacks the carbonyl carbon, forming a tetrahedral intermediate.

Step 3: In part (a), the intermediate undergoes dehydration (loss of water) to form the imine product. The final product will have a C=N bond between the phenyl group of the amine and the carbonyl carbon of acetophenone.

Step 4: Analyze the reaction in part (b). The reactants include an aldehyde (acrolein), hydrazine (H₂N-NH₂), and an acid catalyst (H⁺). This is a typical reaction for hydrazone formation, where the aldehyde reacts with hydrazine to form a C=N bond.

Step 5: In part (b), the mechanism begins with the protonation of the carbonyl oxygen by H⁺, increasing the electrophilicity of the carbonyl carbon. Hydrazine attacks the carbonyl carbon, forming a tetrahedral intermediate. The intermediate undergoes dehydration (loss of water) to form the hydrazone product, which contains a C=N bond between the hydrazine and the aldehyde carbon.

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Key Concepts

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

Imine Formation

Imine formation occurs when a carbonyl compound (like an aldehyde or ketone) reacts with a primary amine. The reaction involves the nucleophilic attack of the amine on the carbonyl carbon, followed by the elimination of water. This process is crucial in organic synthesis, as imines can serve as intermediates in various reactions, including condensation and rearrangement.

Enamine Formation

Enamines are formed when a carbonyl compound reacts with a secondary amine. The reaction involves the nucleophilic attack of the amine on the carbonyl carbon, leading to the formation of a double bond between the nitrogen and the carbon adjacent to the carbonyl. Enamines are valuable intermediates in organic synthesis, particularly in alkylation and acylation reactions.

Acid-Base Catalysis

Acid-base catalysis plays a significant role in the formation of imines and enamines. The presence of an acid (H+) can protonate the carbonyl oxygen, increasing the electrophilicity of the carbonyl carbon and facilitating the nucleophilic attack by the amine. This catalytic step is essential for enhancing the reaction rate and ensuring the successful formation of the desired products.

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