One-electron oxidation of aryl-substituted acetylenes ArC≡CX where X is an electron-withdrawing group gives different products, depending on the X substituent. Acetylenic substrates with medium-strength electron-withdrawing substituents, X = CO2R, COAr, COR, PO(OEt)2, give rise to tetrasubstituted ethenes X(ArCO)C=C(COAr)X. Compounds with strong electron-withdrawing groups (X = COCF3, COCO2R, CN) are converted into furan derivatives. Probable mechanisms of transformations of ArC≡CX radical cations into the final products are discussed. Radical cations derived from disubstituted acetylenes were characterized by ESR spectroscopy.
Предметные области Scopus
- Органическая химия