Used as a reagent in organic synthesis, particularly in methylenation reactions where a carbonyl group is converted to a methylene group. It serves as a sulfur ylide precursor, enabling the formation of carbon-carbon double bonds under mild conditions. Commonly applied in the synthesis of alkenes from aldehydes and ketones, especially in complex molecule construction such as natural products and pharmaceuticals. Its iodide counterion enhances solubility in polar solvents, facilitating reaction efficiency in various synthetic pathways.