IBS-catalyzed regioselective oxidation of phenols to 1,2-quinones with Oxone®.
We have developed the first example of hypervalent iodine(V)-catalyzed regioselective oxidation of phenols to o-quinones. Various phenols could be oxidized to the corresponding o-quinones in good to excellent yields using catalytic amounts of sodium salts of 2-iodobenzenesulfonic acids (pre-IBSes) and stoichiometric amounts of Oxone® as a co-oxidant under mild conditions. The reaction rate of IBS-catalyzed oxidation under nonaqueous conditions was further accelerated in the presence of an inorganic base such as potassium carbonate (K₂CO₃), a phase transfer catalyst such as tetrabutylammonium hydrogen sulfate (nBu₄NHSO₄), and a dehydrating agent such as anhydrous sodium sulfate (Na₂SO₄).
Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603, Japan.
Muhammet
M
Uyanik
Tatsuya
T
Mutsuga
Kazuaki
K
Ishihara
D002254:Carbonates / Q000737:chemistry; D002384:Catalysis; D007455:Iodine / Q000737:chemistry*; D007462:Iodobenzenes / Q000737:chemistry; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry*; D011188:Potassium / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D011809:Quinones / Q000737:chemistry*; D013431:Sulfates / Q000737:chemistry
D002254:Carbonates; D007462:Iodobenzenes; D010636:Phenols; D000644:Quaternary Ammonium Compounds; D011809:Quinones; D013431:Sulfates; C012036:sodium sulfate; D007455:Iodine; C037593:potassium carbonate; C009405:tetrabutylammonium; D011188:Potassium