Amides are derivatives of carboxylic acids, therefore, one strategy to convert aldehydes to amides is by first oxidizing them to carboxylic acids. Once we have the carboxylic acid, we can subject it to condensation with amines using a coupling agent such as DCC or EDC. Alternatively, we can convert the carboxylic acid to acid chloride, which are the most reactive carboxylic acid derivatives, and readily reacts with all types of nucleophiles, including amines:
Aldehydes to Amides via Oxidative Cleavage
If the conversion of the aldehyde to amide shortens the carbon chain, then the process may involve some oxidative cleavage of a π bond. For example, we can convert the aldehyde to an alkene, cleave the double bond, forming a carboxylic acid, and then convert the latter to an amide:
We first convert the aldehyde to an alkene via a reduction and either Zaitsev or Hofmann elimination, and oxidize the alkene to a carboxylic acid by either ozonolysis or KMnO4. Once we have the carboxylic acid, we can condensate it with an amine using a coupling reagent or by converting it to an acid chloride first.
Organic Chemistry Reaction Maps
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