Grignard reaction

Schematic of the Grignard reaction. Reagents: alkyl halide, aryl halide, Magnesium metal, Grignard reagent, electrophile (formaldehyde, aldehyde, ketone, carbon dioxide, nitrile), acid work-up. Product: primary, secondary, or tertiary alcohol, carboxylic acid, ketone. Comments: The example above shows a carbonyl group being converted to an alcohol. A variety of products are possible depending on the electrophile.

The Grignard reaction is an organic reaction used to create a variety of products through the reaction of an organomagnesium compound, also known as a "Grignard reagent" with an electrophile, followed by acid work-up. The Grignard reagent is formed through the reaction of an alkyl or aryl halide with magnesium metal via a radical mechanism. The mechanism of the subsequent reaction of the Grignard reagent with the electrophile is debatable. The most popular proposals are a "concerted mechanism" or another "radical mechanism", both can explain the final addition product.[1][2]


Mechanism of the Grignard reaction. The Grignard reduction mechanism is not fully understood. The two most popular mechanisms are the "Concerted mechanism" which begins with coordination of the metal to the carboxyl oxygen that brings the two molecules closer, and the "Radical mechanism". Both mechanisms lead to the formation of the same intermediate.


Grignard, V. C. R. Acad. Sci. 1900, 130, 1322–1324.
Grignard, V. Ann.Chim. 1901, 7, 433–490.