Resin-OsO4 are very efficient catalysts for the dihydroxylation of various olefins to afford vicinal diols with high yields irrespective of the cooxidant used. Resin-OsO4 is recovered quantitatively by a simple filtration and reused for a number of cycles with consistent activity. The high binding ability of the heterogeneous osmium catalysts enables the use of an equimolar ratio of a chiral ligand such as (DHQD)2PHAL to osmium to give excellent enantioselectives in the asymmetric dihydroxylation.
B. M. Choudary, N. S. Chodari, K. Jyothi, M. L. Kantam, J. Am. Chem. Soc., 2002, 124, 5341-5349.
Osmium tetroxide has been microencapsulated in a polyurea matrix. These microcapsules have been effectively used as recyclable catalysts in the dihydroxylation and the oxidative cleavage of olefins.
S. V. Ley, C. Ramarao, A.-L. Lee, N. Ostergaard, S. C. Smith, I. M. Shirley, Org. Lett., 2003, 5, 185-187.
The cis-dihydroxylation of olefin-containing potassium alkyl- and aryltrifluoroborates proceeds readily in moderate to excellent yields. The resulting diols are efficient coupling partners in Suzuki-Miyaura-type reactions with both alkenyl and aryl bromides.
G. A. Molander, R. Figueroa, Org. Lett., 2006, 8, 75-78.
The OsO4-catalyzed direct oxidation of olefins via the carbon-carbon cleavage of an osmate ester by the action of oxone allows the preparation of ketones or carboxylic acids in high yields. This method should be applicable as an alternative to ozonolysis.
B. R. Travis, R. S. Narayan, B. Borhan, J. Am. Chem. Soc., 2002, 124, 3824-3825.
A new one-pot method is described for the removal of O- and N-allyl protecting groups under oxidative conditions at near neutral pH. The allyl group undergoes hydroxylation and subsequent periodate scission of the vicinal diol. Repetition of this reaction sequence on the enole tautomer of the aldehyde intermediate releases the deprotected functional group.
P. I. Kitov, D. R. Bundle, Org. Lett., 2004, 3, 2835-2838.