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.
Gas-phase oxygenation of benzene derivatives around 300 K with O(3P) atoms produced by microwave discharge of N2O. Part 2. Kinetic H/D isotope effects.
Sol, Veronica M.,Louw, Robert,Mulder, Peter
, p. 346 - 352 (2007/10/02)
The possible pathways for the formation of (chloro)phenol, following the addition of O(3P) to (chloro)benzene, have been examined using deuterated substrates: C6D6 (also in admixture with C6H6) and p-deuterochlorobenzene.Whereas with O-C6H6 adduct biradicals, loss of H* to give phenoxy radicals predominates, only one-third of the O-C5D6 intermediates undergo the corresponding reaction.Phenoxy radicals lead to phenol by transfer of an H(D) atom from cyclohexadienyl-type radicals, formed from H* (D*) and substrate.Analogously, in reactions of p-deuterochlorobenzene, loss of H is a major reaction after addition of an oxygen atom to a meta position, whereas loss of D (to give p-chlorophenol) occurs only with 35percent of the corresponding O(3P) adduct biradicals.The isotopic composition of phenol formed from p-DC6H4Cl (via p-DC6H4O*; generated by ipso substitution) revealed that H transfer to phenoxy radicals primarily gives the keto tautomers as major products.Isomerization of (chloro)benzene-O(3P) adduct biradicals to the corresponding phenols also appears to involve mainly, keto tautomers.The reaction of O(3P) with p-deuterochlorobenzene showed a slight change in the o/m/p distribution; this can be explained by the absence of a net secondary H/D isotope effect for O(3P) addition to the para site and a normal secondary isotope effect for meta addition.
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.
