Catalytic asymmetric dihydroxylation using phenoxyethoxymethyl-polystyrene (PEM)-based novel microencapsulated osmium tetroxide (PEM-MC OsO4)

reaction: see text]. A phenoxyethoxymethyl-polystyrene (PEM)-based novel polymer-supported osmium catalyst has been developed. The catalyst was readily prepared from PEM polymer based on a microencapsulation technique, and asymmetric dihydroxylation of olefins has been successfully performed using (DHQD)2PHAL as a chiral ligand and K3Fe(CN)6 as a cooxidant in H2O/acetone. The catalyst was recovered quantitatively by simple filtration and reused without loss of activity several times.