Fluorous Oxime Palladacycle: A Precatalyst for Carbon-Carbon Coupling Reactions in Aqueous and Organic Medium

To facilitate precatalyst recovery and reuse, we have developed a fluorous, oxime-based palladacycle 1 and demonstrated that it is a very efficient and versatile precatalyst for a wide range of carbon carbon bond formation reactions (Suzuki-Miyaura, Sonogashira, Stille, Heck, Glaser-type, and Kumada) in either aqueous or organic medium under microwave irradiation. Palladacycle 1 could be recovered through F-SPE in various coupling reactions with recovery ranging from 84 to 95% for the first cycle. Inductively coupled plasma optical emission spectrometry (ICP-OES) analyses of the Pd content in the crude product from each class of transformation indicated extremely low levels of leaching and the palladacycle could be reused four to five times without significant loss of activity.