Synthesis of Enamines Stork Enamine Reactions

Aldehydes and ketones react with secondary amines to form compounds called enamines. The general reaction for enamine formation can be written as follows  

Since enamine formation requires the loss of a molecule of water, enamine preparations are usually carried out in a way that allows water to be removed as an azeotrope or by a drying agent. This removal of water drives the reversible reaction to completion. Enamine formation is also catalyzed by the presence of a trace of an acid. The secondary amines most commonly used to prepare enamines are cyclic amines such as pyrrolidine, piperidine, and morpholine  

Cyclohexanone, for example, reacts with pyrrolidine in the following way  

Enamines are good nucleophiles. Examination of the resonance structures that follow show that we should expect enamines to have both a nucleophilic nitrogen and a nucleophilic carbon. A map of electrostatic potential highlights the nucleophilic region of an enamine. 

Contribution to the hybrid made by this structure confers nucieophiiicity on nitrogen. 

---