Abstract
A regioselective C–H arylation of substituted phenols or naphthols with substituted aromatics in the presence of K2S2O8 and Bu4N+·HSO4– in CF3COOH at ambient temperature providing unsymmetrical biaryls is described. The cross-coupling reaction is compatible with various substituted phenols and aromatics. Based on oxidation potential studies, it was observed that phenols with oxidation potentials up to 0.68 V and naphthols up to 0.88 V were compatible with the reaction. The cross-coupling reaction proceeds through the reaction of K2S2O8 with substituted phenol, providing a cationic phenol radical intermediate that was further converted into the phenoxy radical intermediate by the dissociation of H+. Subsequent radical-anion coupling of the phenoxy radical intermediate with a substituted aromatic affords the cross-coupling product. The formation of a cationic phenol radical intermediate and phenoxy radical intermediate were confirmed by UV/Vis and EPR studies.
Original language | English |
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Pages (from-to) | 4305-4312 |
Number of pages | 8 |
Journal | European Journal of Organic Chemistry |
Volume | 2017 |
Issue number | 29 |
DOIs | |
State | Published - 10 Aug 2017 |
Externally published | Yes |
Keywords
- Biaryls
- Cross-coupling
- Oxidative coupling
- Phenols
- Radical reactions
- Regioselectivity
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry