Catalytic hypervalent iodine oxidation using 4-iodophenoxyacetic acid and oxone: oxidation of p-alkoxyphenols to p-benzoquinones.
A catalytic hypervalent iodine oxidation of p-alkoxyphenols using 4-iodophenoxyacetic acid (1a) and Oxone((R)) was developed. Reaction of p-alkoxyphenol (2) with a catalytic amount of 1a in the presence of Oxone((R)) as a co-oxidant in 2,2,2-trifluoroethanol-water (1 : 2) gave the corresponding p-quinone (3) in excellent yield without special operation. The substituent effect on iodobenzene ring in the oxidation was observed; p-alkoxy is the most effective, with the series following the approximate order p-RO>p-Me, o-MeO, m-MeO>H>o-CO(2)H. And remarkable solvent effects were observed.
Yakura
Takayuki
T
Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani, Toyama 930-0194, Japan. yakura@pha.u-toyama.ac.jp
Tian
Yuan
Y
Yamauchi
Yû
Y
Omoto
Masanori
M
Konishi
Tatsuya
T
D000438:Alcohols / Q000737:chemistry; D016227:Benzoquinones / Q000138:chemical synthesis / Q000737:chemistry*; D002384:Catalysis; D007455:Iodine / Q000737:chemistry*; D007462:Iodobenzenes / Q000737:chemistry*; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry*; D013464:Sulfuric Acids / Q000737:chemistry*
C534660:4-iodophenoxyacetic acid; D000438:Alcohols; D016227:Benzoquinones; D007462:Iodobenzenes; D010636:Phenols; D013464:Sulfuric Acids; C059688:alkoxyl radical; D007455:Iodine; C048813:potassium peroxymonosulfuric acid