Among all the possible organometallics, tin (Stille coupling), 4 boron derivatives (Suzuki−Miyaura coupling), 5 and to a lesser extent organozinc (Negishi coupling), organomagnesium (Kumada coupling), and organosilicon reagents (Hiyama) have been the most frequently used. 3 To promote these coupling reactions, various metal catalysts have been used and particular attention has been paid to palladium complexes. 3,6 The uncatalyzed synthesis of the biphenyl system ...
