Palladium-catalyzed cross-coupling reactions of potassium alkenyltrifluoroborates with organic halides in aqueous media

One mol % Pd loading of 4-hydroxyacetophenone oxime derived palladacycle or Pd[(OAc).sub.2] as precatalysts, [K.sub.2]C[O.sub.3] as base and water as additive was used to cross-couple potassium vinyl and alkenyltrifluoroborates with aryl and heteroaryl bromides to yield styrenes, stilbenoids, and alkneylbenzenes. These simple phosphine-free reaction conditions facilitate the palladium recycling from the aqueous phase during up to five runs by extractive separation of the products, which contain 58-105 ppm of Pd.