Electrosynthesis of dimeric butenolides by C-C-homocoupling in the oxidation of 2,4-diarylfurans under aqueous conditions
Belen Batanero,
Noemi Salardon,
Elena Prieto-Garcés,
Lorena Herrera,
Soufyane Er-Ryhy,
M. Teresa Quirós,
Natalia Gómez-Casanova,
Irene Heredero-Bermejo,
José Luis Copa-Patiño
Affiliations
Belen Batanero
University of Alcala, Department of Organic Chemistry and Inorganic Chemistry and Institute of Chemical Research Andrés M. del Rio, 28805 Alcala de Henares, Madrid, Spain; Corresponding author
Noemi Salardon
University of Alcala, Department of Organic Chemistry and Inorganic Chemistry and Institute of Chemical Research Andrés M. del Rio, 28805 Alcala de Henares, Madrid, Spain
Elena Prieto-Garcés
University of Alcala, Department of Organic Chemistry and Inorganic Chemistry and Institute of Chemical Research Andrés M. del Rio, 28805 Alcala de Henares, Madrid, Spain
Lorena Herrera
University of Alcala, Department of Organic Chemistry and Inorganic Chemistry and Institute of Chemical Research Andrés M. del Rio, 28805 Alcala de Henares, Madrid, Spain
Soufyane Er-Ryhy
University of Alcala, Department of Organic Chemistry and Inorganic Chemistry and Institute of Chemical Research Andrés M. del Rio, 28805 Alcala de Henares, Madrid, Spain
M. Teresa Quirós
University of Alcala, Department of Organic Chemistry and Inorganic Chemistry and Institute of Chemical Research Andrés M. del Rio, 28805 Alcala de Henares, Madrid, Spain
Natalia Gómez-Casanova
University of Alcala, Department of Biomedicine and Biotechnology, 28805 Alcalá de Henares, Spain
Irene Heredero-Bermejo
University of Alcala, Department of Biomedicine and Biotechnology, 28805 Alcalá de Henares, Spain
José Luis Copa-Patiño
University of Alcala, Department of Biomedicine and Biotechnology, 28805 Alcalá de Henares, Spain
Summary: Fast and efficient galvanostatic conversion of 2,4-diarylfurans into dimeric furan-2(5H)-ones is now possible in one pot and good yields at room temperature in sustainable aqueous organic solvent. Recent applications of these highly desired structures demand our attention since they are a versatile alternative to acrylates in polymerization to achieve green materials. The reaction mechanism proposal, supported by density functional theory (DFT) theoretical calculations, involves furanoxy radicals, detected by electron paramagnetic resonance (EPR), as the last intermediate before a homocoupling step that affords butenolides. The process can be successfully extended to an array of electron-donating and electron-withdrawing substituents on the aromatic ring. The proposed pathways to explain the formation of the products are rationalized and discussed. A concomitant oxidation of water to hydroxyl radicals is not discarded, particularly with electron-withdrawing substituents at the aromatic ring. In addition, the biological activity as biocides of the obtained compounds was tested, and they showed promising activity against Staphylococcus aureus.
