Decorated palladium nanoparticles on chitosan/δ-FeOOH microspheres: A highly active and recyclable catalyst for Suzuki coupling reaction and cyanation of aryl halides.

In this study, an eco-friendly and low cost magnetic nanocomposite consisting of chitosan/δ-FeOOH microspheres (CS/δ-FeOOH) was fabricated as a stabilizer by using a simple method. Pd nanoparticles (Pd NPs) were decorated on the designed CS/δ-FeOOH, and the resulting Pd NPs@CS/δ-FeOOH microspheres were employed as a heterogeneous catalyst in the construction of biaryl and benzonitriles. Pd NPs@CS/δ-FeOOH microspheres efficiently catalyzed the conversion of aryl iodides and bromides to the desired biaryls within 3 h. Moreover, Pd NPs@CS/δ-FeOOH microspheres showed high catalytic potential against synthesis of benzonitriles by providing yields up to of 99% within 4 h. More importantly, it was proved that Pd NPs@CS/δ-FeOOH microspheres were able to be easily recycled and reused up to eight runs for both reactions. This study reveals that Pd NPs@CS/δ-FeOOH microspheres are useful and recyclable nanocatalysts, which catalyze the synthesis of biaryl and benzonitriles with good reaction yields.