Efficient Stille cross-coupling reaction using aryl chlorides or bromides in water.

An efficient Stille cross-coupling reaction using a variety of aryl halides in neat water has been developed. Employing palladium-phosphinous acid catalyst [(t-Bu)(2)P(OH)](2)PdCl(2) allows formation of biaryls from aryl chlorides and bromides in good to high yields. Functional groups such as ketones and nitriles are tolerated, and organic cosolvents are not required. The air stability and solubility in water of the palladium complexes used in this study facilitate operation of the coupling reaction and product isolation. The feasibility of catalyst recycling has also been demonstrated.