Answer
Grignard reagents, organometallic compounds of magnesium, are primarily employed in organic synthesis for their remarkable ability to form carbon-carbon bonds. These versatile reagents are formed by the reaction of an alkyl or aryl halide with magnesium metal in an ethereal solvent. Grignard reagents act as powerful nucleophiles, readily reacting with various electrophiles, including carbonyl compounds, to construct new carbon-carbon bonds.