Recyclable Magnetic Nanoparticle-Supported Iodoarene Catalysts for Oxidation of 4-Alkoxyphenols to Quinones

Iodoarene catalysts immobilized on magnetite (Fe3O4) were developed. The reactivity of catalysts 4a and 4b were similar to that of 4-iodophenoxyacetic acid (3) for the oxidation of 4-alkoxyphenols in the presence of Oxone((R)) as a co-oxidant to give the corresponding p-quinones in high yields. In addition, 4b was readily recovered by the use of an external magnet and was recycled up to eight times. This is the first example of a magnetic, nanoparticle-supported iodoarene catalyst.