Enamine formation: acetone reacts with dimethylamine. What is the product?

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Enamine formation: acetone reacts with dimethylamine. What is the product?

Enamine formation happens when a ketone reacts with a secondary amine. The ketone and the secondary amine first form a condensed intermediate that loses water to give an iminium ion; then deprotonation at the alpha carbon creates a carbon–carbon double bond, yielding an enamine. For acetone and dimethylamine, the product is the enamine where the dimethylamino group is attached to the carbon of the double bond: CH3-CH=C(NMe2)-CH3. The double bond forms next to the nitrogen-containing center, which is characteristic of enamines derived from ketones with secondary amines. This is different from an imine (which would come from a primary amine) or an amide (which would involve cleavage/addition pathways not operative here).

Enamine formation happens when a ketone reacts with a secondary amine. The ketone and the secondary amine first form a condensed intermediate that loses water to give an iminium ion; then deprotonation at the alpha carbon creates a carbon–carbon double bond, yielding an enamine.

For acetone and dimethylamine, the product is the enamine where the dimethylamino group is attached to the carbon of the double bond: CH3-CH=C(NMe2)-CH3. The double bond forms next to the nitrogen-containing center, which is characteristic of enamines derived from ketones with secondary amines. This is different from an imine (which would come from a primary amine) or an amide (which would involve cleavage/addition pathways not operative here).

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