Grignard Reagent
An organomagnesium halide that acts as a source of a carbanion-like nucleophilic carbon.
Formula / equation
R–Mg–X
Unit
Dimensionless
In depth
Prepared from a haloalkane and magnesium turnings in dry ether, the reagent has a strongly polarised C–Mg bond that makes carbon nucleophilic. It attacks carbonyl compounds to form new carbon–carbon bonds, but is destroyed instantly by any water, alcohol or acid.
Examples in the real world
Adding a Grignard reagent to methanal gives a primary alcohol, to a ketone a tertiary alcohol.