Professor Lawrence Que, Jr., University of Minnesota

Professor Lawrence Que, Jr., University of Minnesota
Date
Fri February 5th 2016, 4:00pm
Location
Braun Lecture Hall
S.G. Mudd Building
Stanford University

"In Pursuit of the Elusive Fe(V)=O Oxidant in C–H and C=C Bond Oxidations by Bio-inspired Nonheme Iron Catalysts"

About the Seminar:

Inspired by the versatile oxidation chemistry catalyzed by nonheme iron enzymes, we have been investigating C–H and C=C bond oxidations by H2O2 that are catalyzed by nonheme iron complexes of neutral tetradentate ligands. Highly stereoselective hydroxylation of cis­-1,2-dimethylcyclohexane andcis-dihydroxylation of olefins can be observed. Carboxylic acid additives further enhance the efficacy of these catalysts. Experiments designed to gain insight into how the catalysis occurs such as product distribution studies and 18O labeling experiments have implicated a mechanism involving an oxoiron(V) oxidant. Our latest attempts to trap the active species and characterize its spectroscopic properties will be described.

About the Speaker:

Lawrence Que, Jr. is the Regents Professor of the University of Minnesota. He received his B.S. degree in Chemistry from Ateneo de Manila University in 1969 and Ph.D. degree in Chemistry from University of Minnesota in 1973. After postdoctoral studies, one with Professor Richard H. Holm at Massachusetts Institute of Technology (1973-74) and another with Eckard Münck at Gray Freshwater Biological Institute (1975-77), Professor Que started his independent career as an Assistant Professor of Chemistry at Cornell University in 1977. In 1983, Professor Que moved to the University of Minnesota.

Professor Que’s group focuses on bio-inorganic chemistry, specifically on the topic of iron, oxygen and biocatalysis. Their research effort, involving a combination of biochemical, synthetic inorganic, and spectroscopic approaches, is aimed at elucidating the oxygen activation mechanisms of nonheme iron enzymes, designing functional models for such enzymes, trapping and characterizing reaction intermediates, and developing bio-inspired oxidation catalysts for green chemistry applications. For more information about Professor Que and his accomplishments, please refer to his website.