ORGN 433 |
| We are exploring the use of electrochemical methods to promote asymmetric hydrogenation reactions. In an effort to achieve this goal, we have constructed chiral modified electrodes via electrochemical oxidation of metal complexes containing chiral ligands (i.e., palladium or ruthenium bis(oxazoline) complexes) that are tethered to electropolymerizable molecules (i.e., terthiophene). Electrochemically-promoted hydrogenation reactions using modified electrodes based on palladium bis(oxazoline) complexes produced high yields of hydrogenated products but, unfortunately, racemic mixtures were obtained. The activity of ruthenium-based electrodes is currently under investigation. We are also investigating electrochemically-promoted hydrogenation of prochiral substrates using chiral catalysts dissolved in solution. Our most successful results were obtained using cationic [Rh(DuPHOS)(COD)] complexes. Electrochemistry and NMR studies revealed that single electron reduction of [Rh(DuPHOS)(COD)][OTf] resulted in ejection of the COD ligand and binding of a prochiral substrate to the metal. Asymmetric hydrogenation reactions using this system is currently under investigation and will be discussed. |
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ACS Award for Research at an Undergraduate Institution
8:00 AM-12:00 PM, Wednesday, 29 March 2006 Georgia World Congress Center -- C303/304/305, Oral
Division of Organic Chemistry |