Suzuki–Miyaura coupling under air in water promoted by polymer supported palladium nanoparticles

Suzuki couplings of aryl bromides were efficiently performed by a polymer supported palladium catalyst under air in water at 100 °C without additives. In the case of activated aryl chlorides the reactions proceeded smoothly in the presence of a suitable phase transfer agent. The catalyst was active and recyclable for at least five times. Atomic absorption analyses revealed that the metal content in the polymeric support did not significantly decrease with the cycles while inductively coupled plasma analyses revealed that the palladium amount both in the mother liquors and in the organic products after reactions was lower than 500 ppb. The activity of the mother liquors has been investigated in detail. A transmission electron microscopy study of the supported catalyst before, during and after duty is also described.

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► A polymer supported palladium catalyst (Pd-pol) promoted the Suzuki reaction.
► Pd-pol was active in the coupling of aryl bromides and chlorides under air in water.
► The catalyst could be reused at least five times with negligible loss of activity.
► Pd leaching was analyzed in detail.
► The leached active species may re-deposit onto the insoluble support.