Magnetically Recoverable Osmium Catalysts with Osmium-Diolate Esters for Dihydroxylation of Olefins

We prepared magnetically recoverable osmium catalysts with stable osmium–diolate esters and applied them to the dihydroxylation of olefins. By employing 2 mol% of the magnetic osmium catalyst, the dihydroxylation reaction proceeded smoothly to provide the corresponding vicinal diol with a low level of osmium leaching. After completion of the dihydroxylation, the osmium catalyst was readily recovered by use of an external magnet and was recycled up to five times.