The Bouveault aldehyde synthesis (also known as the Bouveault reaction) is a one-pot substitution reaction that replaces an alkyl or aryl halide with a formyl group using a N,N-disubstituted formamide.
For primary alkyl halides this produces the homologous aldehyde one carbon longer. For aryl halides this produces the corresponding carbaldehyde.
Bouveault aldehyde synthesis is an example of a formylation reaction.