Fall 2009 Courses

[CHEM-35600] Nuclear Magnetic Resonance

[CHEM-22200] Organic Chemsitry 2

Research in Organic Chemistry

The unifying theme in my research lab is organic synthesis, but our research projects have been highly varied.

One project we've worked on involves the synthesis of molecules that are structurally modified versions of the well known antioxidant Vitamin E, in hopes that these new molecules will target mitochondria in cells (which is where the majority of oxidative damage occurs). This would prove useful in combating diseases such as Alzheimer's, Parkinson's, Lou Gehrig's, and various cancers.

Several students have also worked with reactive molecules known as stable silylenes and have explored the application of these compounds as catalysts in new organometallic reactions. Stable silylenes are excellent metal ligands and have shown to act as phenomenal catalysts (similar to phosphines) in certain organic reactions. The Stille reaction, for example, can employ palladium-silylene complexes to create new C-C bonds between molecules. Our research is involved with designing, testing, and observing the mechanisms of such catalysts.

Microfluidics has proven to show great promise in the world of synthetic chemistry, and the third area of our research deals with developing and refining new techniques in this field. Moving beyond the standard "reaction pot" methods, microfluidics involves a mobile liquid phase (dissolved or pure reagent) which flows through a tiny reaction chamber. A second reagent is injected directly into the mobile phase chamber (much like a stream would flow into a river), creating thousands of tiny, isolated reactions. The product is then collected as the mobile phase carries it to the end of the reaction vessel.

We are continuing to study an interesting organic reaction that affords tertiary amines from alkyl nitriles under palladium catalyzed reducing conditions.  The outcome of these reactions can change depending on the solvent choice, and afford products in nearly quantitative yields.

One of our newest projects deals with the synthesis of organometallic catalysts designed to make biodegradable polymers from non-petroleum resources.  Specifically, we are exploring the ring-opening polymerization (ROP) of lactide to polylactic acid (PLA) via the use of aluminum based catalysts.  Because lactide monomer can be produced via the fermentation of corn or sugar beets, the polymerization of lactide to PLA represents a carbon-neutral process.  As such, this polymer has been the subject of high interest, and it is already manufactured in large quantitites for use in applications such as absorbable sutures, biodegradable flatware, and packaging material. ROP is a useful route to study, as it affords careful control over the polymers physical and chemical properties.  This work is being done in collaboration with Professor Charlotte Williams at Imperial College in London.

Research Group Homepage

Biography

EDUCATION
B.S. in chemistry, Ithaca College, 1994
Ph.D. in chemistry, University of Wisconsin-Madison, 2000 Research Advisor: Robert West

TEACHING EXPERIENCE
University of Wisconsin-Baraboo, 1997-1999.
Elizabethtown College, 2000-2002.

Selected Publications

Steinbacher, Jeremy L.; Moy, Rebecca W. Y.; Price, Price, Kristin E.; Cummings, Meredith A.; Roychowdhury, Chandrani; Buffy, Jarrod, J.; Olbricht, William L.; Haaf, Michael, McQuade, D. Tyler, "Rapid Self-Assembly of Core-Shell Organosilicon Microcapsule within a Microfluidic Device" Journal of the American Chemical Society, 2006, 128, 9442- 9447.

Poe, Sarah L.; Cummings, Meredith A.; Haaf, Michael P.; McQuade, D. Tyler. "Solving the clogging problem: precipitate-forming reactions in flow." Angewandte Chemie, International Edition, 2006, 45, 1544-1548.

X. Zhang, M. Haaf, E. Grosstephan, Henry Schierembergg, B. Todorich, J. R. Connor, “Cytokine Toxicity to Oligodendrocyte Precursors is Mediated by Iron,” Glia 2005, 52, 199.

Amoroso, Dino; Haaf, Michael; Yap, Glenn P. A.; West, Robert; Fogg, Deryn E.   "A Stable Silylene in a Reactive Environment: Synthesis, Reactivity, and Silicon Extrusion Chemistry of a Coordinatively Unsaturated Ruthenium Silylene Complex Containing Chloride and h 3-P-C-P Ligands."  Organometallics, 2002,  21(3), 534-540.

Schmedake, Thomas A.; Haaf, Michael; Paradise, Bryan J.; Millevolte, Anthony J.; Powell, Douglas R.; West, Robert.   Electronic and steric properties of stable silylene ligands in metal(0) carbonyl complexes.    Journal of Organometallic Chemistry, 2001, 636, 17-25. 

West, Robert; Schmedake, Thomas A.; Haaf, Michael; Becker, James; Mueller, Thomas.   "A disilanyl dianion and a silyl dianion from a stable silylene."    Chemistry Letters,  2001, 1,  68-69.

Haaf, Michael; Schmedake, Thomas A.; Paradise, Bryan J.; West, Robert.   "Synthesis and reactivity of the stable silylene N,N'-di-tert-butyl-1,3-diaza-2-sila-2-ylidene."    Canadian Journal of Chemistry, 2000,  78, 1526-1533.

Haaf, Michael; Schmedake, Thomas A.; West, Robert.   "Stable Silylenes."    Accounts of Chemical Research, 2000,  33, 704-714. 

Haaf, Michael; Schmiedl, Andreas; Schmedake, Thomas A.; Powell, Douglas R.; Millevolte, Anthony J.; Denk, Michael; West, Robert.   Synthesis and Reactivity of a Stable Silylene.    Journal of the American Chemical Society, 1998,  120, 12714-12719. 

Selected Student Presentations

King, Ryan W.; Deering, Dustin M.; Haaf, Michael.   Stable silylenes as catalysts in C-C bond forming reactions.    Abstracts of Papers, 231st ACS National Meeting, Atlanta, GA, United States, March 26-30, 2006.

Cummings, Meredith A.; Haaf, Michael; McQuade, D. Tyler; Steinbacher, Jeremy; Poe, Sarah L.; Moy, Rebecca.   Precipitate forming reactions in a simplified microfluidic device.    Abstracts of Papers, 231st ACS National Meeting, Atlanta, GA, United States, March 26-30, 2006.

Grosstephan, Erin; Schierembergg, Henry; Morse, Sonya; Connor, James R.; Zhang, Xuesheng; Haaf, Michael.   Synthesis of mitochondrially targeted antioxidants.    Abstracts of Papers, 229th ACS National Meeting, San Diego, CA, United States, March 13-17, 2005.

Sangi, Michael; Lassen, Kenneth; Hill, Nick; Haaf, Michael.   Stille reactions catalyzed by a silylene-palladium complex.    Abstracts of Papers, 229th ACS National Meeting, San Diego, CA, United States, March 13-17, 2005.

West, Robert; Moser, Daniel F.; Haaf, Michael; Schmedake, Thomas A.; Guzei, Ilia.   New reactions of stable silylenes.    Organosilicon Chemistry V: From Molecules to Materials, [Scientific Contributions presented at the European Silicon Days], 1st, Munich, Germany, Sept., 2001  (2003),  Meeting Date 2001, 19-26.