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The discovery of cinchona-derived phthalazine-based ligands and the selective use of organic sulfonamides open the way to a simpler osmium-catalyzed asymmetric dihydroxylation (AD) of olefins. Four classes of olefins, when reacted with an AD-mix of dihydroquinidine or dihydroquinine phthalazides, yield corresponding diols with over 90% enantiomeric excess. Mirror-image matching is also closer than when quinidine and quinine ligands are used. The addition of methanesulfonamide to tri- and 1,2-di-substituted (but not for terminal) olefins permits milder reaction conditions and the use of less catalyst and chiral ligand.

A new class of ligands, bis-cinchona alkaloid substituted pyrimidine ligands result in enhanced enantioselectivity in the osmium-catalyzed asymmetric dihydroxylation (AD) of monosubstituted terminal olefins, and provide remarkable prospects for terminal olefins. Diphenylpyrimidine ligand is characterizied by a 5-phenyl group twisted at 90 degrees to the pyrimidine ring. The 2-phenyl groups lies in a plane which almost coincides with the plane of pyrimidine ring. The substrates phathalazines and its DHQ analog exhibit affinity for the diphenylpyrimidine ligands and monosubstitutd terminal olefins, which are characterized by branching in the substituent.