Alkylating and Acylating the a-Carbon Using an Enamine Intermediate

8 ALKYLATING AND ACYLATING THE a-CARBON USING AN ENAMINE INTERMEDIATE 

We have seen that an enamine is formed when an aldehyde or a ketone reacts with a secondary amine (Section 17.10). 

Enamines react with electrophiles in the same way that enolate ions do. 

As a result, aldehydes and ketones can be alkylated at the a-carbon via an enamine intermediate  

Because the alkylation step is an Sn2 reaction, only primary alkyl halides or methyl halides should be used (Section 9.2). The main advantage to using an enamine intermediate to alkylate an aldehyde or a ketone is that it forms a monoalkylated product without having to use a strong base (LDA). 

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