74383-28-1Relevant articles and documents
Ortho-Selective Hydrogen Isotope Exchange of Phenols and Benzyl Alcohols by Mesoionic Carbene-Iridium Catalyst
Zhao, Liang-Liang,Wu, Yixin,Huang, Shiqing,Zhang, Zengyu,Liu, Wei,Yan, Xiaoyu
supporting information, p. 9297 - 9302 (2021/11/30)
Hydrogen isotope exchange reactions of phenols and benzyl alcohols have been achieved by a mesoionic carbene-iridium catalyst with high ortho selectivity and high functional group tolerance. Control experiments indicated that acetate is crucial to realize the ortho selectivity, whereas density functional theory calculations supported an outer-sphere direction with hydrogen bonding between acetate and the hydroxyl group.
Mechanism of Aromatic Hydroxylation in the Fenton and Related Reactions. One-Electron Oxidation and the NIH Shift
Kurata, Tsunehiko,Watanabe, Yasumasa,Katoh, Makoto,Sawaki, Yasuhiko
, p. 7472 - 7478 (2007/10/02)
Hydroxylation of substituted benzenes in the Fenton and peroxydisulfate oxidations has been studied mechanistically in relation to the NIH shift.One-electron oxidants such as Fe3+, Cu2+, and quinones increased the shift value effectively in aqueous or acetonitrile solutions.The shift values obtained were as high as 40 - 50 percent and dependent on both substituents (i. e., MeO Me, Cl, MeCO) and solvents.A high shift value was obtained also for the methoxylation, indicating unimportance of the arene oxide intermediate for the NIH shift.Oxygen reduced the shift effectively and sometimes was incorporated into product phenols with selective meta orientation.The means that oxygen abstracts a hydrogen atom from or adds to the oxycyclohexadienyl radical intermediate.It is concluded that the one-electron oxidation of the dienyl radical is the key step for the shift and its rates are dependent on substituents, oxidants, and solvents.
