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.
[1][2] For primary alkyl halides this produces the homologous aldehyde one carbon longer.
The first step of the Bouveault aldehyde synthesis is the formation of the Grignard reagent.
Upon addition of a N,N-disubstituted formamide (such as dimethylformamide) a hemiaminal is formed, which can easily be hydrolyzed into the desired aldehyde.
Variants using organolithium reagents instead of magnesium-based Grignard reagents are also considered Bouveault aldehyde syntheses.