A Mild and Versatile Method for Palladium-Catalyzed Cross-Coupling of Aryl Halides in Water and Surfactants

Various aqueous surfactants proved to be excellent media for carrying out palladium‐catalyzed Suzuki−Miyaura cross‐coupling reactions under mild conditions. The dehalogenation side reaction, which is usually a drawback with the aqueous protocol, was not observed. The concentration of the surfactant in water played a pivotal role for the reaction outcome. Smooth cross‐coupling of iodoanisole and a variety of aryl bromides, including electron‐rich derivatives, with aryl boronic acids occurred at room temperature in high yields either with [Pd(PPh3)4] or Pd/C as catalyst. The water‐surfactant Pd/C system combines high activity under ambient conditions (air), easy separation and recyclability. Palladium acetate was found to be effective in cross‐coupling of the less reactive aryl chlorides at 100 °C. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)