A magnetically retrievable mixed-valent FeO@SiO/Pd/Pd nanocomposite exhibiting facile tandem Suzuki coupling/transfer hydrogenation reaction.

Herein, we report a magnetically retrievable mixed-valent FeO@SiO/Pd/PdNP (5) nanocomposite system for tandem Suzuki coupling/transfer hydrogenation reaction. The nanocomposite 5 was prepared first by making a layer of [Formula: see text] on [Formula: see text] followed by deposition of [Formula: see text] and sorption of [Formula: see text] ions successively onto the surface of FeO@SiONP. The nanocomposite was characterized by powder XRD, electron microscopy (SEM-EDS and TEM-EDS) and XPS spectroscopy techniques. The mixed-valent [Formula: see text] present onto the surface of nanocomposite 5 was confirmed by XPS technique. Interestingly, the mixed-valent nanocomposite FeO@SiO/Pd/PdNP (5) exhibited tandem Suzuki coupling/transfer hydrogenation reaction during the reaction of aryl bromide with aryl boronic acid (90% of C). The nanocomposite 5 displayed much better reactivity as compared to the monovalent FeO@SiO/PdNP (3) (25% of C) and FeO@SiO/PdNP (4) (15% of C) nanocomposites. Further, because of the presence of magnetic [Formula: see text], the nanocomposite displayed its facile separation from the reaction mixture and reused at least for five catalytic cycles.