title: Activation of Electron-Deficient Quinones through Hydrogen-Bond-Donor-Coupled Electron Transfer.
abstract: Quinones are important organic oxidants in a variety of synthetic and biological contexts, and they are susceptible to activation towards electron transfer through hydrogen bonding. Whereas this effect of hydrogen bond donors (HBDs) has been observed for Lewis basic, weakly oxidizing quinones, comparable activation is not readily achieved when more reactive and synthetically useful electron-deficient quinones are used. We have successfully employed HBD-coupled electron transfer as a strategy to activate electron-deficient quinones. A systematic investigation of HBDs has led to the discovery that certain dicationic HBDs have an exceptionally large effect on the rate and thermodynamics of electron transfer. We further demonstrate that these HBDs can be used as catalysts in a quinone-mediated model synthetic transformation.
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138 (USA).
authors.forename: Amanda K
authors.initials: AK
authors.lastname: Turek
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138 (USA).
authors.forename: David J
authors.initials: DJ
authors.lastname: Hardee
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138 (USA).
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Ullman
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138 (USA). dnocera@fas.harvard.edu.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Nocera
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138 (USA). jacobsen@chemistry.harvard.edu.
authors.forename: Eric N
authors.initials: EN
authors.lastname: Jacobsen
mesh_terms: D004583:Electrons; D006860:Hydrogen Bonding; D007700:Kinetics; D011809:Quinones / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D011809:Quinones
keywords: catalysis; electron transfer; hydrogen bonding; oxidation; quinones