New Osmium-Based Reagent for the Dihydroxylation of Alkenes

The cis dihydroxylation of alkenes is most efficiently accomplished by reaction with osmium tetroxide.
Recently, the expense and toxicity of osmium tetroxide have led to a number of attempts to harness
alternative osmium-based reagents, including microencapsulation and solid support techniques. We describe
here the development of a new nonvolatile, stable, and recoverable osmium-based reagent devised for
the stoichiometric cis dihydroxylation of alkenes. Although attempts to make this new dihydroxylation
work with catalytic amounts of this reagent were unsuccessful, we did develop a sensitive test for free
osmium tetroxide leached from the reagent in situ:  this test may well have uses in probing future
applications of derivatized osmium reagents.