Related Experiment Video
Updated: Feb 16, 2026

Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts
Published on: February 24, 2015
Substituent Effects in Chain-Breaking Aryltellurophenol Antioxidants
Jia-Fei Poon1, Jiajie Yan1, Kjell Jorner2
1Department of Chemistry, Biomedicinskt Centrum (BMC), Uppsala University, Box-576, 751 23, Uppsala, Sweden.
Abstract:
2-Aryltellurophenols substituted in the aryltelluro or phenolic parts of the molecule were prepared by lithiation of the corresponding tetrahydropyran-protected 2-bromophenol, followed by reaction with a suitable diaryl ditelluride then deprotection. In a two-phase system containing N-acetylcysteine as a co-antioxidant in the aqueous phase, all of the compounds quenched lipid peroxyl radicals more efficiently than α-tocopherol, with three to five-fold longer inhibition times. Thus, these compounds offer better and longer-lasting antioxidant protection than recently prepared alkyltellurophenols. Compounds with electron-donating para substituents in the aryltelluro or phenolic part of the molecule showed the best results. The mechanism for quenching peroxyl radicals was considered and discussed with respect to the calculated O-H bond-dissociation energies, deuterium-labelling experiments and studies of thiol consumption in the aqueous phase.
More Related Videos
06:34Synthesis of Antiviral Tetrahydrocarbazole Derivatives by Photochemical and Acid-catalyzed C-H Functionalization via Intermediate Peroxides CHIPS
Published on: June 20, 2014
11:44Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions
Published on: March 20, 2014
Related Concept Videos
Nucleophilic Aromatic Substitution: Addition–Elimination (SNAr)
The reaction begins with an attack of the nucleophile on the carbon that holds the leaving group. This results in the delocalization of the π electrons over the ring carbons. The resonance interaction between...
Directing and Steric Effects in Disubstituted Benzene Derivatives
Regioselectivity of Electrophilic Additions-Peroxide Effect
Nucleophilic Aromatic Substitution: Elimination–Addition
meta-Directing Deactivators: –NO2, –CN, –CHO, –⁠CO2R, –COR, –CO2H
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3