Catalytic Asymmetric Dihydroxylation of Olefins with Reusable OsO42- on Ion-Exchangers: The Scope and Reactivity Using Various Cooxidants
Boyapati M. Choudary,* Naidu S. Chowdari, Karangula Jyothi and Mannepalli L. Kantam
*Indian Institute of Chemical Technology, Hyderabad 500 007, India, Email: bmchoudaryyahoo.com
B. M. Choudary, N. S. Chodari, K. Jyothi, M. L. Kantam, J. Am. Chem. Soc., 2002, 124, 5341-5349.
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.
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