Prof. Larry Que, University of Minnesota

Hydrocarbon oxidations by bio-inspired nonheme iron catalysts

School Colloquia

Inspired by the versatile oxidation chemistry catalyzed by nonheme iron enzymes, we have been investigating the iron-catalyzed oxidations of hydrocarbons. 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). Insights into the catalytic mechanism have been obtained from a combination of product distribution studies, 18O labeling experiments, spectroscopic characterization of intermediates trapped at low temperature, and DFT calculations. These results implicate an FeV=O oxidant. In a related study, hydrocarbon oxidation is observed for a biomimetic iron complex that reacts with O2. The shape selectivity observed for this reaction is quite unusual, suggesting that substrate recognition can be elicited even in a relatively simple model complex.

For more information contact Prof. Jake Soper (404-894-4022).