CHED 848 |
| We have been investigating the iron-catalyzed oxidations of olefins by H2O2 as inspired by the oxidation chemistry of nonheme iron enzymes. Highly stereoselective conversions of olefins to epoxides and/or cis-diols have been observed with the use of Fe(N4)(OTf)2 complexes where N4 is a tetradentate ligand with four nitrogen donor sites such as TPA (TPA = tris(2-pyridylmethyl)amine) and BPMEN (BPMEN = N,N'-bis(2-pyridylmethyl)-N,N'-dimethyl-1,2-diaminothane). The nature of the oxidizing species is a question of great interest, and possible oxidants include Fe(III)-OOH, Fe(IV)=O and Fe(V)=O species. Insights into the catalytic mechanisms of these complexes have been obtained from a combination of product distribution studies with different olefin substrates, 18O labeling experiments, spectroscopic characterization of intermediates trapped at low temperature, and DFT calculations. Our current views on how these bio-inspired oxidations work will be presented |
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Exploring and Exploiting Nature with Biomimetics
1:30 PM-4:45 PM, Monday, March 26, 2007 McCormick Place North -- Room N230A, Level 2, Oral
Division of Chemical Education |