80572-92-5Relevant academic research and scientific papers
Multi-Electron Oxidation of Anthracene Derivatives by Nonheme Manganese(IV)-Oxo Complexes
Sharma, Namita,Jung, Jieun,Lee, Yong-Min,Seo, Mi Sook,Nam, Wonwoo,Fukuzumi, Shunichi
, p. 7125 - 7131 (2017)
Six-electron oxidation of anthracene to anthraquinone by a nonheme MnIV-oxo complex, [(Bn-TPEN)MnIV(O)]2+, proceeds through a rate-determining electron transfer from anthracene to [(Bn-TPEN)MnIV(O)]2+, followed by subsequent fast oxidation reactions to give anthraquinone. The reduced MnII complex ([(Bn-TPEN)MnII]2+) is oxidized by [(Bn-TPEN)MnIV(O)]2+ rapidly to produce the μ-oxo dimer ([(Bn-TPEN)MnIII-O-MnIII(Bn-TPEN)]4+). The oxygen atoms of the anthraquinone product were found to derive from the manganese-oxo species by the 18O-labelling experiments. In the presence of Sc3+ ion, formation of an anthracene radical cation was directly detected in the electron transfer from anthracene to a Sc3+ ion-bound MnIV(O) complex, [(Bn-TPEN)MnIV(O)-(Sc(OTf)3)2]2+, followed by subsequent further oxidation to yield anthraquinone. When anthracene was replaced by 9,10-dimethylanthracene, electron transfer from 9,10-dimethylanthracene to [(Bn-TPEN)MnIV(O)-(Sc(OTf)3)2]2+ occurred rapidly to produce stable 9,10-dimethylanthracene radical cation. The driving force dependence of the rate constants of electron transfer from the anthracene derivatives to [(Bn-TPEN)MnIV(O)]2+ and [(Bn-TPEN)MnIV(O)-(Sc(OTf)3)2]2+ was well-evaluated in light of the Marcus theory of electron transfer.
PhIO-Mediated oxidative dethioacetalization/dethioketalization under water-free conditions
Du, Yunfei,Ouyang, Yaxin,Wang, Xi,Wang, Xiaofan,Yu, Zhenyang,Zhao, Bingyue,Zhao, Kang
, p. 48 - 65 (2021/06/16)
Treatment of thioacetals and thioketals with iodosobenzene in anhydrous DCM conveniently afforded the corresponding carbonyl compounds in high yields under water-free conditions. The mechanistic studies indicate that this dethioacetalization/dethioketalization process does not need water and the oxygen of the carbonyl products comes from the hypervalent iodine reagent.
The Oxo-Wall Remains Intact: A Tetrahedrally Distorted Co(IV)-Oxo Complex
Dong, Hai T.,Larson, Virginia A.,Lee, Yong-Min,Lehnert, Nicolai,Nam, Wonwoo,Seo, Mi Sook,Shearer, Jason,Yang, Jindou
, p. 16943 - 16959 (2021/10/25)
In this paper, we report the preparation, spectroscopic and theoretical characterization, and reactivity studies of a Co(IV)-oxo complex bearing an N4-macrocyclic coligand, 12-TBC (12-TBC = 1,4,7,10-tetrabenzyl-1,4,7,10-tetraazacyclododecane). On the basis of the ligand and the structure of the Co(II) precursor, [CoII(12-TBC)(CF3SO3)2], one would assume that this species corresponds to a tetragonal Co(IV)-oxo complex, but the spectroscopic data do not support this notion. Co K-edge XAS data show that the treatment of the Co(II) precursor with iodosylbenzene (PhIO) as an oxidant at -40 °C in the presence of a proton source leads to a distinct shift in the Co K-edge, in agreement with the formation of a Co(IV) intermediate. The presence of the oxo group is further demonstrated by resonance Raman (rRaman) spectroscopy. Interestingly, the EPR data of this complex show a high degree of rhombicity, indicating structural distortion. This is further supported by the EXAFS data. Using DFT calculations, a structural model is developed for this complex with a ligand-protonated structure that features a Co?O···HN hydrogen bond and a four-coordinate Co center in a seesaw-shaped coordination geometry. Magnetic circular dichroism (MCD) spectroscopy further supports this finding. The hydrogen bond leads to an interesting polarization of the Co-oxo ?-bonds, where one O(p) lone-pair is stabilized and leads to a regular Co(d) interaction, whereas the other ?-bond shows an inverted ligand field. The reactivity of this complex in hydrogen atom and oxygen atom transfer reactions is discussed as well.
Manganese(Ⅲ)-iodosylbenzene complex, preparation method thereof and oxidant comprising the same
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Paragraph 0103, (2020/09/22)
The present invention relates to a manganese(III)-iodosylbenzene complex, a preparation method thereof, and an oxidant comprising the same. The manganese(III)-iodosylbenzene complex provided in one aspect of the present invention has an effect of inducing a hydrogen atom abstraction (HAA) reaction of cyclohexadiene, dihydroanthracene and xanthine, and an oxygen atom transfer (OAT) reaction of thioanisole and stilbene with excellent electrophilic reactivity. The manganese(III)-iodosylbenzene complex is represented by a compound of formula 1: [Mn^III(L)(OIPh)(OH)]^2+.COPYRIGHT KIPO 2020
Oxidation of Naphthalene with a Manganese(IV) Bis(hydroxo) Complex in the Presence of Acid
Jeong, Donghyun,Yan, James J.,Noh, Hyeonju,Hedman, Britt,Hodgson, Keith O.,Solomon, Edward I.,Cho, Jaeheung
supporting information, p. 7764 - 7768 (2018/06/26)
Naphthalene oxidation with metal–oxygen intermediates is a difficult reaction in environmental and biological chemistry. Herein, we report that a MnIV bis(hydroxo) complex, which was fully characterized by various physicochemical methods, such as ESI-MS, UV/Vis, and EPR analysis, X-ray diffraction, and XAS, can be employed for the oxidation of naphthalene in the presence of acid to afford 1,4-naphthoquinone. Redox titration of the MnIV bis(hydroxo) complex gave a one-electron reduction potential of 1.09 V, which is the most positive potential for all reported nonheme MnIV bis(hydroxo) species as well as MnIV oxo analogues. Kinetic studies, including kinetic isotope effect analysis, suggest that the naphthalene oxidation occurs through a rate-determining electron transfer process.
Structure and Reactivity of a Mononuclear Nonheme Manganese(III)-Iodosylarene Complex
Jeong, Donghyun,Ohta, Takehiro,Cho, Jaeheung
supporting information, p. 16037 - 16041 (2018/12/13)
Transition metal-iodosylarene complexes have been proposed to be key intermediates in the catalytic cycles of metal catalysts with iodosylarene. We report the first X-ray crystal structure and spectroscopic characterization of a mononuclear nonheme manganese(III)-iodosylarene complex with a tetradentate macrocyclic ligand, [MnIII(TBDAP)(OIPh)(OH)]2+ (2). The manganese(III)-iodosylarene complex is capable of conducting various oxidation reactions with organic substrates, such as C-H bond activation, sulfoxidation and epoxidation. Kinetic studies including isotope labeling experiments and Hammett correlation demonstrate the electrophilic character on the Mn-iodosylarene adduct. This novel intermediate would be prominently valuable for expanding the chemistry of transition metal catalysts.
Halogen-Bonding-Assisted Iodosylbenzene Activation by a Homogenous Iron Catalyst
De Sousa, David P.,Wegeberg, Christina,Vad, Mads Sorensen,Morup, Steen,Frandsen, Cathrine,Donald, William A.,McKenzie, Christine J.
, p. 3810 - 3820 (2016/03/08)
The iron(III) complex of hexadentate N,N,N′-tris(2-pyridylmethyl)ethylendiamine-N′-acetate (tpena-) is a more effective homogenous catalyst for selective sulfoxidation and epoxidation with insoluble iodosylbenzene, [PhIO]n, compared with soluble methyl-morpholine-N-oxide (NMO). We propose that two molecules of [Fe(tpena)]2+ cooperate to solubilize PhIO, extracting two equivalents to form the halogen-bonded dimeric {[Fe(tpena)OIPh]2}4+. The closest intradimeric I...O distance, 2.56 ?, is nearly 1 ? less than the sum of the van de Waals radii of these atoms. A correlation of the rates of the reaction of {[Fe(tpena)OIPh]2}4+ with para-substituted thioanisoles indicate that this species is a direct metal-based oxidant rather than a derived ferryl or perferryl complex. A study of gas-phase reactions indicate that an ion at m/z=231.06100 originates from solution-state {[Fe(tpena)OIPh]2}4+ and is ascribed to [FeIII(tpenaO)]2+, derived from an intramolecular O atom insertion into an Fe-tpena donor bond. Proposed ion pairs, {[Fe(tpena)OIPh]Cl}+ and {[Fe(tpena)OIPh]ClO4}+, are more stable than native [Fe(tpena)OIPh]2+ ions, suggesting that halogen-bonding, as for the solution and solid states, operates also in the gas phase.
Interplay of Experiment and Theory in Elucidating Mechanisms of Oxidation Reactions by a Nonheme RuIVO Complex
Dhuri, Sunder N.,Cho, Kyung-Bin,Lee, Yong-Min,Shin, Sun Young,Kim, Jin Hwa,Mandal, Debasish,Shaik, Sason,Nam, Wonwoo
, p. 8623 - 8632 (2015/07/15)
A comprehensive experimental and theoretical study of the reactivity patterns and reaction mechanisms in alkane hydroxylation, olefin epoxidation, cyclohexene oxidation, and sulfoxidation reactions by a mononuclear nonheme ruthenium(IV)-oxo complex, [RuIV(O)(terpy)(bpm)]2+ (1), has been conducted. In alkane hydroxylation (i.e., oxygen rebound vs oxygen non-rebound mechanisms), both the experimental and theoretical results show that the substrate radical formed via a rate-determining H atom abstraction of alkanes by 1 prefers dissociation over oxygen rebound and desaturation processes. In the oxidation of olefins by 1, the observations of a kinetic isotope effect (KIE) value of 1 and styrene oxide formation lead us to conclude that an epoxidation reaction via oxygen atom transfer (OAT) from the RuIVO complex to the C-C double bond is the dominant pathway. Density functional theory (DFT) calculations show that the epoxidation reaction is a two-step, two-spin-state process. In contrast, the oxidation of cyclohexene by 1 affords products derived from allylic C-H bond oxidation, with a high KIE value of 38(3). The preference for H atom abstraction over C-C double bond epoxidation in the oxidation of cyclohexene by 1 is elucidated by DFT calculations, which show that the energy barrier for C-H activation is 4.5 kcal mol-1 lower than the energy barrier for epoxidation. In the oxidation of sulfides, sulfoxidation by the electrophilic Ru-oxo group of 1 occurs via a direct OAT mechanism, and DFT calculations show that this is a two-spin-state reaction in which the transition state is the lowest in the S = 0 state.
Isolation, Purification, and Characterization of Intermediate (Iodosylbenzene)metalloporphyrin Complexes from the (Tetraphenylporphinato)manganese(III)-Iodosylbenzene Catalytic Hydrocarbon Functionalization System
Smegal, John A.,Schardt, Bruce C.,Hill, Craig L.
, p. 3510 - 3515 (2007/10/02)
A second-type of high-valent complex has been isolated from the reaction of (tetraphenylporphinato)manganese(III) derivatives, XMnIIITPP, with iodosylbenzene.This new type of complex, isolated from the XMnIIITPP-iodosylbenzene system
