Microencapsulated Osmium Tetroxide‐Catalyzed Asymmetric Dihydroxylation of Olefins in Water without Using Organic Cosolvents

The asymmetric dihydroxylation of olefin using phenoxyethoxymethyl-polystyrene (PEM)-based microencapsulated osmium tetroxide (PEM-MC OsO4) proceeded smoothly in water as the sole solvent. The catalyst was recovered quantitatively by simple filtration and reused several times without loss of activity.