Nontoxic, nonvolatile, and highly efficient osmium catalysts for asymmetric dihydroxylation of alkenes and application to one mol-scale synthesis of an anticancer drug, camptothecin intermediate

Novel polymer-incarcerated osmium (PI Os) catalysts have been developed. The Os catalysts were shown to be nontoxic and nonvolatile, and stable for several months in air. Asymmetric dihydroxylation of alkenes using these Os catalysts proceeded smoothly to afford the corresponding diols in high yields with high enantioselectivities. The catalysts could be recovered and reused. One mol-scale preparation of a key intermediate for camptothecin, an anticancer drug, has also been successfully demonstrated by using the catalysts.