The Stille reaction is a chemical reaction that involves the coupling of an organostannane with an alkene or alkyne in the presence of a palladium catalyst. This reaction is useful for forming carbon-carbon bonds, making it valuable in organic synthesis, particularly in the production of complex molecules. In the Stille reaction, the organostannane acts as a nucleophile, while the alkene or alkyne serves as the electrophile. The reaction typically occurs under mild conditions and can tolerate various functional groups, making it a versatile tool for chemists in the development of pharmaceuticals and other organic compounds.