Bouveault aldehyde synthesis

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The Bouveault aldehyde synthesis (also known as Bouveault reaction ) is a reaction from the field of organic chemistry . It was discovered by Louis Bouveault in 1896 and named after him. This reaction is an aldehyde synthesis. For this purpose, an N , N- disubstituted formamide is reacted with a Grignard reagent or an organolithium compound .

Overview reaction

The Bouveault reaction is a method for the production of aldehydes from a formamide (R = methyl, ethyl, phenyl) and a Grignard compound (R = methyl, ethyl, phenyl; X = Cl, Br or I):

Synthesis of aldehydes from formamides;  R = methyl, ethyl, phenyl;  X = Cl, Br or I

It is important that an N , N -disubstituted formamide is used, since unsubstituted formamides do not yield aldehydes. It does not matter which disubstituted formamide is used for the reaction, the yield of aldehydes in this synthesis corresponds to approx. 40-80%.

mechanism

The Bouveault reaction is very complicated. Therefore it only works in certain cases. Sometimes tertiary amines and hydrocarbons are produced as by-products. If an N , N -disubstituted formamide is reacted with a Grignard compound in a ratio of 1: 3, the main product is a tertiary amine instead of the desired aldehyde. When a methyl formamide is reacted with a Grignard compound in a ratio of 1: 1, the main product is the desired aldehyde. When using diethylformamide, only the aldehyde is formed. It has been found that as the organic residue of the Grignard compound increases, the yield of aldehyde increases.

Mechanism for the production of aldehydes;  R = methyl, ethyl, phenyl;  X = Cl, Br or I [3]

First, the Grignard compound (R = methyl, ethyl, phenyl; X = Cl, Br or I) attacks the carbon atom of the carbonyl compound (R = methyl, ethyl, phenyl). The aldehyde is then formed via two intermediate products.

Individual evidence

  1. ^ L. Bouveault: Modes de formation et de preparation des aldéhydes saturées de la serie grasse. In: Bulletin de la Société chimique de Paris. XXXI, 1904, pp. 1306-1322 ( digitized on Gallica ).
  2. ^ L. Bouveault: Nouvelle méthode générale synthétique de preparation des aldéhydes. In: Bulletin de la Société chimique de Paris . XXXI, 1904, pp. 1322-1327 ( digitized on Gallica ).
  3. a b c d Z. Wang (Ed.): Comprehensive Organic Name Reactions and Reagents, 3 Volume Set . John Wiley & Sons, Hoboken, New Jersey 2009, ISBN 978-0-471-70450-8 , pp. 490-491.
  4. H. Krauch, W. Kunz: Name reactions of organic chemistry . Dr. Alfred Hüthig, Heidelberg 1961, p. 67.