Used primarily in organic synthesis, this compound serves as a key reagent for methylenation reactions, particularly in the preparation of alkenes from aldehydes and ketones via the Wittig reaction. It is especially effective for introducing a terminal double bond in a molecule, making it valuable in the synthesis of complex organic structures such as pharmaceuticals, natural products, and functionalized olefins. Its stability and reactivity profile make it a preferred choice over more sensitive phosphonium salts. The iodide counterion enhances solubility in polar solvents, facilitating its use in a wide range of reaction conditions.