Very efficient and broad-in-scope palladium-catalyzed Hiyama cross-coupling. The role of water and copper(I) salts

A very high-yielding Pd-catalyzed cross-coupling between aryl halides and aryl(trialkoxy)silanes is achieved in the presence of Cu(I) and a measured amount of water. This novel methodology is useful for the generation of a wide range of biaryls, particularly non-para substituted derivatives, which are usually less reported.