Electrosynthesis of dimeric butenolides by C-C-homocoupling in the oxidation of 2,4-diarylfurans under aqueous conditions.

Fast and efficient galvanostatic conversion of 2,4-diarylfurans into dimeric furan-2(5)-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.