Thermally accelerated Heck reaction under direct mechanocatalysis using palladium milling balls†

We present a direct mechanocatalytic approach for the Mizoroki–Heck coupling of aryl iodides with olefins using palladium milling balls as catalyst under elevated temperatures in a ball milling reactor. The high chemoselectivity for C(sp²)–I bonds ensures a single product when employing multi-halogenated arenes. Additionally, a one-pot Wittig olefination/Heck cross-coupling enables direct access to stilbene derivatives from aldehydes and aryl iodides without intermediate isolation.