Nickel(II)–aryl complexes as catalysts for the Suzuki cross-coupling reaction of chloroarenes and arylboronic acids

A series of air- and moisture-stable Ni(II)–(σ-aryl) complexes, Ni(PPh3)2(aryl)X (X = Cl, Br), were employed as catalyst precursors in the Ni-catalyzed Suzuki cross-coupling reaction. These pre-catalysts easily form the catalytically active Ni(0) species in situ without the need of additional reducing agents. A general catalytic system involving Ni(PPh3)2(1-naph)Cl and PPh3 proved to be highly effective for the Suzuki reaction of aryl chlorides under mild conditions (at 60 °C in THF in the presence of K2CO3 as the base).