Asymmetric Alkene Hydrogenation

The asymmetric hydrogenation of olefins is one of the most powerful reactions for the synthesis of single enantiomer products. Carbon-hydrogen bonds are most common constituent in chiral centers further the power of asymmetric alkene hydrogenation to access single enantiomer compounds. In collaboration with the Merck Catalysis Laboratory and with funding from the National Science Foundation (Acc. Chem. Res. 2015, 48, 1687.), we have developed two new classes of cobalt catalysts for asymmetric alkene hydrogenation. The first are C1-symmetric, redox-active bis(imino)pyridine cobalt compounds that are rare examples of catalysts that promote the asymmetric hydrogenation of minimally functionalized alkenes (J. Am. Chem. Soc. 2012, 134, 4561.; J. Am. Chem. Soc. 2016, 138, 3314.). Cooperative metal-ligand redox is likely operative during the catalytic cycle and the cobalt(II) oxidation is maintained throughout.

The second class of compounds utilizes bidentate phosphine ligands and enables hydrogenation of functionalized alkenes such as those more typically found in drug-like molecules (Science 2013, 342, 1076.). Mechanistic studies support a more precious metal-like two-electron redox couple.

Selected Publications

Cobalt-Catalyzed Enantioselective Hydrogenation of Minimally Functionalized Alkenes: Isotopic Labeling Provides Insight into the Origin of Stereoselectivity and Alkene Insertion Preferences
Max R. Friedfeld, Michael Shevlin, Grant W. Margulieux, Louis-Charles Campeau, and Paul J. Chirik
J. Am. Chem. Soc. 2016, 138, 3314-3324.

Cobalt Precursors for High-Throughput Discovery of Base Metal Asymmetric Alkene Hydrogenation Catalysts
Max R. Friedfeld, Michael Shevlin, Jordan M. Hoyt, Shane W. Krska, Matthew T. Tudge, Paul J. Chirik
Science 2013, 342, 1076-1080.

Enantiopure C1-Symmetric Bis(imino)pyridine Cobalt Complexes for Asymmetric Alkene Hydrogenation
Sebastien Monfette, Zoë R. Turner, Scott P. Semproni, and Paul J. Chirik
J. Am. Chem. Soc. 2012, 134, 4561-4564.