Return to Contents  Chapter 17: Aldehydes and Ketones. Nucleophilic Addition to C=O  Ch 17 contents

Reactions of Secondary Amine Derivatives

preparation of enamines
                                                                          enamine
Reaction type:  Nucleophilic Addition then Elimination

Summary

Related Reactions
NUCLEOPHILIC ADDITION OF A SECONDARY AMINE GIVING AN ENAMINE

 

Step 1:
An acid/base reaction. Protonation of the carbonyl activates it and makes it more susceptible to attack by a neutral nucleophilic like the N of a secondary amine

formation of an enamine
Step 2:
Attack of the N nucleophile at the electrophilic C of the C=O group with the electrons from the π bond going to the +ve O.
Step 3:
An acid/base reaction. Removal of the proton neutralises the +ve charge on the N and forms the carbinolamine intermediate.
Step 4:
To form the enamine we need to dehydrate. However, before -OH leaves it needs to be protonated, so a simple acid/base reaction.
Step 5:
Removal of a proton from an adjacent C allows the C=C π bond to form and loss of the leaving group, a neutral water molecule, creating the enamine.

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© Dr. Ian Hunt, Department of Chemistry, University of Calgary