Forming carbon-carbon bonds is notoriously difficult, making this reaction essential for building the complex organic frameworks used in modern pharmaceuticals.

Adding the reagent to an aldehyde or ketone breaks its carbon-oxygen double bond, creating an intermediate that becomes an alcohol when treated with acid.

Because these reagents are extremely strong bases, they rapidly strip protons from any trace of water to instantly form a useless, unreactive alkane.

Inserting a magnesium atom between a carbon and a halogen shifts electrons toward the carbon, transforming the organic molecule into a powerful nucleophile.