<P> Grignard reactions and reagents were discovered by and are named after the French chemist François Auguste Victor Grignard (University of Nancy, France), who published it in 1900 and was awarded the 1912 Nobel Prize in Chemistry for this work . Grignard reagents are similar to organolithium reagents because both are strong nucleophiles that can form new carbon--carbon bonds . The nucleophilicity increases if the alkyl substituent is replaced by an amido group . These amido magnesium halides are called Hauser bases . </P> <P> The Grignard reagent functions as a nucleophile, attacking the electrophilic carbon atom that is present within the polar bond of a carbonyl group . The addition of the Grignard reagent to the carbonyl typically proceeds through a six - membered ring transition state . </P> <P> However, with hindered Grignard reagents, the reaction may proceed by single - electron transfer . Similar pathways are assumed for other reactions of Grignard reagents, e.g., in the formation of carbon--phosphorus, carbon--tin, carbon--silicon, carbon--boron and other carbon--heteroatom bonds . </P> <P> Grignard reagents form via the reaction of an alkyl or aryl halide with magnesium metal . The reaction is conducted by adding the organic halide to a suspension of magnesium in an etherial solvent, which provides ligands required to stabilize the organomagnesium compound . Empirical evidence suggests that the reaction takes place on the surface of the metal . The reaction proceeds through single electron transfer: In the Grignard formation reaction, radicals may be converted into carbanions through a second electron transfer . </P>

Treatment of acetaldehyde with ethyl magnesium bromide and subsequent hydrolysis give