ORGN 553 |
| Aza(bisoxazoline) ligands are distinctively different from the related bis(oxazoline) ligands in their electronic properties and moreover, facile immobilization with various supports through the central nitrogen is possible. For example, racemic 1,2-diols and 1,2-hydroxy carbonyl compounds can be asymmetrically benzoylated in a kinetic resolution in the presence of various Cu(II)-azabis(oxazolines) catalysts. A novel bisbenzyl substituted aza(bisoxazoline) ligand proved to be especially effective when immobilized on MeOPEG5000, giving 91-99% ee in 37-49% yield for each of five sequential reactions. Other reactions, such as conjugate reductions or conjugate additions will be also discussed.
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Asymmetric Reactions and Syntheses
1:00 PM-5:00 PM, Wednesday, 31 August 2005 Washington DC Convention Center -- 201, Oral
Division of Organic Chemistry |
