Tributylstannyliodomethane is primarily used in organic synthesis as a reagent for the introduction of methylene groups into various compounds. It is particularly valuable in Stille coupling reactions, where it facilitates the formation of carbon-carbon bonds, enabling the synthesis of complex organic molecules. This compound is also employed in the preparation of organotin derivatives, which are useful in catalysis and as intermediates in the production of pharmaceuticals and agrochemicals. Additionally, it plays a role in the modification of polymers and the synthesis of organometallic compounds, contributing to advancements in materials science and industrial chemistry.