Oxidative 1,2-Difunctionalization of Ethylene via Gold-Catalyzed Oxyarylation

Oxidative 1,2-Difunctionalization of Ethylene via Gold-Catalyzed Oxyarylation
Matthew J. Harper†, Edward J. Emmett, John F. Bower , and Christopher A. Russell

School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
Syngenta, Jealott’s Hill International Research Centre, Bracknell, Berkshire RG42 6EY, United Kingdom

Link:J. Am. Chem. Soc., 2017, 139 (36), pp 12386–12389

DOI: 10.1021/jacs.7b06668
Publication Date (Web): August 22, 2017



Abstract



Under the conditions of oxidative gold catalysis, exposure of ethylene to aryl silanes and alcohols generates products of 1,2-oxyarylation. This provides a rare example of a process that allows catalytic differential 1,2-difunctionalization of this feedstock chemical.

Standard Reduction Potentials for Oxygen and Carbon Dioxide Couples in Acetonitrile and N,N‑Dimethylformamide

Standard Reduction Potentials for Oxygen and Carbon Dioxide Couples in Acetonitrile and N,N‑Dimethylformamide

Michael L. Pegis,† John A. S. Roberts,‡,∥ Derek J. Wasylenko,§,⊥ Elizabeth A. Mader,† Aaron M. Appel,*,‡ and James M. Mayer*,†

† Department of Chemistry, Yale University, PO Box 208107, New Haven, Connecticut 06520-8107, United States ‡ Center for Molecular Electrocatalysis, Pacific Northwest National Laboratory, P.O. Box 999 (K2-57), Richland, Washington 99352, United States § Department of Chemistry, University of Washington, Campus Box 351700, Seattle, Washington 98195-1700, United States

Inorg. Chem. DOI: 10.1021/acs.inorgchem.5b02136

Abstract:

A variety of next-generation energy processes utilize the electrochemical interconversions of dioxygen and water as the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). Reported here are the first estimates of the standard reduction potential of the O2 + 4e − + 4H+ ⇋ 2H2O couple in organic solvents. The values are +1.21 V in acetonitrile (MeCN) and +0.60 V in N,N-dimethylformamide (DMF), each versus the ferrocenium/ferrocene couple (Fc+/0) in the respective solvent (as are all of the potentials reported here). The potentials have been determined using a thermochemical cycle that combines the free energy for transferring water from aqueous solution to organic solvent, −0.43 kcal mol−1 for MeCN and −1.47 kcal mol−1 for DMF, and the potential of the H+ /H2 couple, − 0.028 V in MeCN and −0.662 V in DMF. The H+ /H2 couple in DMF has been directly measured electrochemically using the previously reported procedure for the MeCN value. The thermochemical approach used for the O2/H2O couple has been extended to the CO2/CO and CO2/CH4 couples to give values of −0.12 and +0.15 V in MeCN and −0.73 and −0.48 V in DMF, respectively. Extensions to other reduction potentials are discussed. Additionally, the free energy for transfer of protons from water to organic solvent is estimated as +14 kcal mol−1 for acetonitrile and +0.6 kcal mol−1 for DMF.

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