Stille coupling is a chemical reaction used in organic synthesis to form carbon-carbon bonds. It involves the coupling of an organostannane (a compound containing tin) with an organic halide (a compound containing a halogen) in the presence of a palladium catalyst. This reaction is valued for its ability to create complex molecules efficiently. The Stille coupling is particularly useful in the synthesis of pharmaceuticals and natural products. It allows for the formation of diverse structures, making it a powerful tool in the field of medicinal chemistry. The reaction conditions can be mild, which helps preserve sensitive functional groups in the starting materials.