What is the Difference Between Hofmann and Curtius Rearrangement?
🆚 Go to Comparative Table 🆚The Hofmann and Curtius rearrangements are different types of chemical reactions that have applications in organic chemistry. Here are the key differences between the two:
- Starting materials: The Hofmann rearrangement starts with a primary amide and converts it into an amine using a halogen (such as Br2 or Cl2), a base (like OH-), and water. On the other hand, the Curtius rearrangement starts with an acid chloride and converts it into an isocyanate using sodium azide (NaN3) and water.
- Migration: In the Hofmann rearrangement, an alkyl group migrates during the reaction, while in the Curtius rearrangement, an acyl group migrates.
- Intermediate steps: In the Hofmann rearrangement, there is a key rearrangement step where heating results in the breakage of a C-C bond, formation of a C-N bond, and breakage of an N-Br bond. In the Curtius rearrangement, heating the acyl azide results in rearrangement, with nitrogen gas (N2) as the leaving group.
- Final products: The Hofmann rearrangement produces an amine as the final product, while the Curtius rearrangement generates an isocyanate.
Both rearrangement reactions involve the migration of a group, but the migration occurs at different positions and results in different final products.
Comparative Table: Hofmann vs Curtius Rearrangement
The Hofmann and Curtius rearrangements are both organic chemical reactions that involve the migration of a functional group, but they differ in the starting materials and the products formed. Here is a comparison table outlining the differences between the two reactions:
Feature | Hofmann Rearrangement | Curtius Rearrangement |
---|---|---|
Starting Material | Amide | Acyl Azide |
Migrating Group | Alkyl Group | Acyl Group |
Product | Amine | Isocyanate |
Mechanism | Involves the migration of an alkyl group to displace a leaving group, forming an amine. | Involves the migration of an acyl group, forming an isocyanate. |
Both reactions involve a key rearrangement step where a carbon atom migrates to displace a leaving group. In the Hofmann rearrangement, a primary amide is converted into a secondary or tertiary amine, while in the Curtius rearrangement, an acyl azide is converted into an isocyanate.
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- Hyperconjugation vs Resonance
- Fluxionality vs Tautomerism
- Furanose vs Pyranose
- Chiral vs Achiral
- Homoleptic vs Heteroleptic Complexes
- Ostwald Theory vs Quinonoid Theory
- Resonance vs Tautomerism
- Backbonding Hyperconjugation vs Conjugation
- Hall Héroult Process vs Hoopes Process