|Chapter 20: Carboxylic Acid Derivatives. Nucleophilic Acyl Substitution|
Reduction of Amides
(for more detail see Chapter 22)
Reaction type: Nucleophilic Acyl Substitution then Nucleophilic Addition
The nucleophilic H from the hydride reagent adds to the electrophilic C in the polar carbonyl group of the ester. Electrons from the C=O move to the electronegative O creating the tetrahedral intermediate, a metal alkoxide complex.
The tetrahedral intermediate collapses and displaces the O as part of a metal alkoxide leaving group, this produces a highly reactive iminium ion an intermediate.
Rapid reduction by the nucleophilic H from the hydride reagent as it adds to the electrophilic C in the iminium system. π electrons from the C=N move to the cationic N neutralising the charge creating the amine product.
|© Dr. Ian Hunt, Department of Chemistry|