- Oxygen acidity of ring methoxylated 1,1-diarylalkanol radical cations bearing α-cyclopropyl groups. The competition between O-neophyl shift and C-cyclopropyl β-scission in the intermediate 1,1-diarylalkoxyl radicals
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A product and time-resolved kinetic study on the reactivity of the radical cations generated from cyclopropyl(4-methoxyphenyl)phenylmethanol (1) and cyclopropyl[bis(4-methoxyphenyl)]methanol (2) has been carried out in aqueous solution. In acidic solution, 1.+ and 2.+ display very low reactivities toward fragmentation, consistent with the presence of groups at Cα (aryl and cyclopropyl) that after Cα-C β bond cleavage would produce relatively unstable carbon-centered radicals. In basic solution, 1.+ and 2.+ display oxygen acidity, undergoing -OH-induced deprotonation from the α-OH group, leading to the corresponding 1,1-diarylalkoxyl radicals 1r. and 2r., respectively, as directly observed by time-resolved spectroscopy. The product distributions observed in the reactions of 1.+ and 2.+ under these conditions (cyclopropyl phenyl ketone, cyclopropyl(4-methoxyphenyl) ketone, and 4-methoxybenzophenone from 1.+; cyclopropyl(4-methoxyphenyl) ketone and 4,4′- dimethoxybenzophenone from 2.+) have been rationalized in terms of a water-induced competition between O-neophyl shift and C-cyclopropyl β-scission in the intermediate 1,1-diarylalkoxyl radicals 1r. and 2r..
- Bietti, Massimo,Fiorentini, Simone,Pato, Iria Perez,Salamone, Michela
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Read Online
- Efficient and eco-compatible transition metal-free Oppenauer-type oxidation of alcohols
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Catalytic amounts of cheap, non-toxic, easy-to-handle and non-sensitive sodium tert-butoxide are able to promote the dehydrogenative oxidation of a wide array of secondary alcohols using inexpensive benzophenone as the H-acceptor. The corresponding ketones, highly important intermediates and targets throughout life and material sciences, are very selectively obtained under mild conditions.
- Ballester, Jorge,Caminade, Anne-Marie,Majoral, Jean-Pierre,Taillefer, Marc,Ouali, Armelle
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Read Online
- Aquacatalytic aerobic oxidation of benzylic alcohols with a self-supported bipyridyl-palladium complex
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The aerobic oxidation of alcohols was promoted in water under atmospheric molecular oxygen by a readily recyclable self-supported bipyridyl-palladium polymeric complex, which was prepared via construction of a metal-organic framework (MOF) of a bipyridyl-palladium complex bearing carboxylic groups and a copper(II) linker. Copyright
- Osako, Takao,Uozumi, Yasuhiro
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Read Online
- Zwitterion-induced organic-metal hybrid catalysis in aerobic oxidation
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In many metal catalyses, the traditional strategy of removing chloride ions is to add silver salts via anion exchange to obtain highly active catalysts. Herein, we reported an alternative strategy of removing chloride anions from ruthenium trichloride using an organic [P+-N-] zwitterionic compound via multiple hydrogen bond interactions. The resultant organic-metal hybrid catalytic system has successfully been applied to the aerobic oxidation of alcohols, tetrahydroquinolines, and indolines under mild conditions. The performance of zwitterion is far superior to that of many other common Lewis bases or Br?nsted bases. Mechanistic studies revealed that the zwitterion triggers the dissociation of chloride from ruthenium trichloride via nonclassical hydrogen bond interaction. Preliminary studies show that the zwitterion is applicable to catalytic transfer semi-hydrogenation.
- Hu, Rong-Bin,Lam, Ying-Pong,Ng, Wing-Hin,Wong, Chun-Yuen,Yeung, Ying-Yeung
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p. 3498 - 3506
(2021/04/07)
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- V2O5@TiO2 Catalyzed Green and Selective Oxidation of Alcohols, Alkylbenzenes and Styrenes to Carbonyls
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The versatile application of different functional groups such as alcohols (1° and 2°), alkyl arenes, and (aryl)olefins to construct carbon-oxygen bond via oxidation is an area of intense research. Here, we report a reusable heterogeneous V2O5@TiO2 catalyzed selective oxidation of various functionalities utilizing different mild and eco-compatible oxidants under greener reaction conditions. The method was successfully applied for the alcohol oxidation, oxidative scission of styrenes, and benzylic C?H oxidation to their corresponding aldehydes and ketones. The utilization of mild and eco-friendly oxidizing reagents such as K2S2O8, H2O2 (30 % aq.), TBHP (70 % aq.), broad substrate scope, gram-scale synthesis, and catalyst recyclability are notable features of the developed protocol.
- Upadhyay, Rahul,Kumar, Shashi,Maurya, Sushil K.
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p. 3594 - 3600
(2021/07/02)
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- Visible light mediated selective oxidation of alcohols and oxidative dehydrogenation of N-heterocycles using scalable and reusable La-doped NiWO4nanoparticles
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Visible light-mediated selective and efficient oxidation of various primary/secondary benzyl alcohols to aldehydes/ketones and oxidative dehydrogenation (ODH) of partially saturated heterocycles using a scalable and reusable heterogeneous photoredox catalyst in aqueous medium are described. A systematic study led to a selective synthesis of aldehydes under an argon atmosphere while the ODH of partially saturated heterocycles under an oxygen atmosphere resulted in very good to excellent yields. The methodology is atom economical and exhibits excellent tolerance towards various functional groups, and broad substrate scope. Furthermore, a one-pot procedure was developed for the sequential oxidation of benzyl alcohols and heteroaryl carbinols followed by the Pictet-Spengler cyclization and then aromatization to obtain the β-carbolines in high isolated yields. This methodology was found to be suitable for scale up and reusability. To the best of our knowledge, this is the first report on the oxidation of structurally diverse aryl carbinols and ODH of partially saturated N-heterocycles using a recyclable and heterogeneous photoredox catalyst under environmentally friendly conditions.
- Abinaya, R.,Balasubramaniam, K. K.,Baskar, B.,Divya, P.,Mani Rahulan, K.,Rahman, Abdul,Sridhar, R.,Srinath, S.
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p. 5990 - 6007
(2021/08/24)
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- Catalytic Aerobic Oxidation of Alkenes with Ferric Boroperoxo Porphyrin Complex; Reduction of Oxygen by Iron Porphyrin
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We herein describe the development of a mild and selective catalytic aerobic oxidation process of olefins. This catalytic aerobic oxidation reaction was designed based on experimental and spectroscopic evidence assessing the reduction of atmospheric oxygen using a ferric porphyrin complex and pinacolborane to form a ferric boroperoxo porphyrin complex as an oxidizing species. The ferric boroperoxo porphyrin complex can be utilized as an in-situ generated intermediate in the catalytic aerobic oxidation of alkenes under ambient conditions to form oxidation products that differ from those obtained using previously reported ferric porphyrin catalysis. Moreover, the mild reaction conditions allow chemoselective oxidation to be achieved.
- Kimura, Kento,Kurahashi, Takuya,Matsubara, Seijiro,Murano, Shunpei
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supporting information
p. 2493 - 2497
(2021/12/29)
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- Transition-Metal-Free Ring-Opening Reaction of 2-Halocyclobutanols through Ring Contraction
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The present work describes the preparation of halohydrins from 2-halocyclobutanones by means of reactions with Grignard reagents at ?78 °C. We discovered that the prepared cyclobutanols underwent a thermal ring-opening reaction. Depending on the structure of the starting cyclobutanol, different products were formed. More specifically, 1-substituted 2-bromocyclobutan-1-ol was found to open to γ-substituted butyrophenones. A novel 1,3-dihydro-2H-inden-2-ylidene derivative was obtained for indene-derived cyclobutanols. Based on the outcomes of the performed experiments, a mechanism for the ring-opening of cyclobutanols can be proposed.
- ?ubiňák, Marek,Edlová, Tereza,Oeser, Petr,Tobrman, Tomá?
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p. 4958 - 4967
(2021/09/28)
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- METHOD FOR OXIDATIVE CLEAVAGE OF COMPOUNDS WITH UNSATURATED DOUBLE BOND
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A method for oxidative cleavage of a compound with an unsaturated double bond is provided. The method comprises the following step: (A) providing a compound (I) with an unsaturated double bond, a reagent with trifluoromethyl, and a catalyst; wherein the catalyst is represented by the following formula (II): M(O)mL1yL2z (II); wherein, M, L1, L2, m, y, z, R1, R2 and R3 are defined in the specification; and (B) mixing the compound with an unsaturated double bond and the reagent with a trifluoromethyl to perform an oxidation of the compound with the unsaturated double bond by using the catalyst at air or an oxygen condition to get a compound presented as formula (III):
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Paragraph 0053-0059
(2021/03/19)
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- Method for oxidative cracking of compound containing unsaturated double bonds
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The invention relates to a method for oxidative cracking of a compound containing unsaturated double bonds. The method comprises the following steps: (A) providing a compound (I) containing unsaturated double bonds, a trifluoromethyl-containing reagent and a catalyst, wherein the catalyst is shown as a formula (II): M(O)mL1yL2z (II), M, L1, L2, m, y, z, R1, R2 and R3 being defined in the specification; and (B) mixing the compound containing the unsaturated double bonds and the trifluoromethyl-containing reagent, and performing an oxidative cracking reaction on the compound containing the unsaturated double bonds in the presence of air or oxygen by using the catalyst to obtain a compound represented by formula (III),.
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Paragraph 0108-0114; 0115-0120; 0182-0184
(2021/07/09)
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- METHOD FOR OXIDATIVE CLEAVAGE OF COMPOUNDS WITH UNSATURATED DOUBLE BOND
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A method for oxidative cleavage of a compound with an unsaturated double bond is provided. The method includes the steps of: (A) providing a compound (I) with an unsaturated double bond, a trifluoromethyl-containing reagent, and a catalyst; wherein, the catalyst is represented by Formula (II): M(O)mL1yL2z??(II);wherein, M, L1, L2, m, y, z, R1, R2 and R3 are defined in the specification; and(B) mixing the compound with an unsaturated double bond and the trifluoromethyl-containing reagent to perform an oxidative cleavage of the compound with the unsaturated double bond by using the catalyst in air or under oxygen atmosphere condition to obtain a compound represented by Formula (III):
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Paragraph 0071; 0074
(2021/07/10)
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- B(C6F5)3-Catalyzed Diastereoselective Formal (4 + 1)-Cycloaddition of Vinylcyclopropanes and Et2SiH2
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A formal (4 + 1)-cycloaddition of vinylcyclopropanes and Et2SiH2 to afford 3,4-disubstituted silolanes is reported. The reaction sequence commences with the known B(C6F5)3-catalyzed alkene hydrosilylation with dihydrosilanes. Cleavage of the remaining Si-H bond in the hydrosilylation product assisted by B(C6F5)3 leads to formation of a cyclopropane-stabilized silylium ion. The activated cyclopropane ring is then opened by the in situ-generated borohydride accompanied by ring closure to the silolane. The diastereoselectivity is rationalized by a mechanistic model.
- Long, Peng-Wei,Oestreich, Martin
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supporting information
p. 4834 - 4837
(2021/06/28)
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- Poly(ethylene glycol) dimethyl ether mediated oxidative scission of aromatic olefins to carbonyl compounds by molecular oxygen
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A simple, and practical oxidative scission of aromatic olefins to carbonyl compounds using O2as the sole oxidant with poly(ethylene glycol) dimethyl ether as a benign solvent has been developed. A wide range of monosubstituted,gem-disubstituted, 1,2-disubstituted, trisubstituted and tetrasubstituted aromatic olefins was successfully converted into the corresponding aldehydes and ketones in excellent yields even with gram-scale reaction. Some control experiments were also conducted to support a possible reaction pathway.
- Yu, Tao,Guo, Mingqing,Wen, Simiaomiao,Zhao, Rongrong,Wang, Jinlong,Sun, Yanli,Liu, Qixing,Zhou, Haifeng
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p. 13848 - 13852
(2021/04/22)
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- Method for preparing aldehyde ketone compound through olefin oxidation
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The invention provides a method for preparing an aldehyde ketone compound by olefin oxidation, which relates to an olefin oxidative cracking reaction in which oxygen participates. The method comprises the following specific steps: in the presence of a solvent and an oxidant, carrying out oxidative cracking on an olefin raw material to obtain a corresponding aldehyde ketone product. Compared with the traditional method, the method does not need to add any catalyst or ligand, does not need to use high-pressure oxygen, has the advantages of simple and mild reaction conditions, environment friendliness, low cost, high atom economy and the like, is wide in substrate application range and high in yield, and has a wide application prospect in the aspects of synthesis of aldehyde ketone medical intermediates and chemical raw materials.
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Paragraph 0019
(2021/04/07)
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- Oxidative Cleavage of Alkenes by O2with a Non-Heme Manganese Catalyst
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The oxidative cleavage of C═C double bonds with molecular oxygen to produce carbonyl compounds is an important transformation in chemical and pharmaceutical synthesis. In nature, enzymes containing the first-row transition metals, particularly heme and non-heme iron-dependent enzymes, readily activate O2 and oxidatively cleave C═C bonds with exquisite precision under ambient conditions. The reaction remains challenging for synthetic chemists, however. There are only a small number of known synthetic metal catalysts that allow for the oxidative cleavage of alkenes at an atmospheric pressure of O2, with very few known to catalyze the cleavage of nonactivated alkenes. In this work, we describe a light-driven, Mn-catalyzed protocol for the selective oxidation of alkenes to carbonyls under 1 atm of O2. For the first time, aromatic as well as various nonactivated aliphatic alkenes could be oxidized to afford ketones and aldehydes under clean, mild conditions with a first row, biorelevant metal catalyst. Moreover, the protocol shows a very good functional group tolerance. Mechanistic investigation suggests that Mn-oxo species, including an asymmetric, mixed-valent bis(μ-oxo)-Mn(III,IV) complex, are involved in the oxidation, and the solvent methanol participates in O2 activation that leads to the formation of the oxo species.
- Bennett, Elliot L.,Brookfield, Adam,Guan, Renpeng,Huang, Zhiliang,Mcinnes, Eric J. L.,Robertson, Craig M.,Shanmugam, Muralidharan,Xiao, Jianliang
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supporting information
p. 10005 - 10013
(2021/07/19)
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- Radical-mediated aerobic oxidation of substituted styrenes and stilbenes
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A 2,2-azobis(isobutyronitrile)-catalyzed oxidative cleavage of alkenes with molecular oxygen as the oxidant was described. Carbonyl compounds and oxiranes were obtained in moderate yield under mild conditions. This study provided useful insights into the mechanism of aerobic oxidative cleavage of alkenes.
- Aman, Hasil,Chiu, Wei-Hua,Chuang, Gary Jing,Liu, Pin-Heng
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supporting information
p. 20103 - 20106
(2021/12/02)
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- Base-free oxidation of alcohols enabled by nickel(ii)-catalyzed transfer dehydrogenation
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An efficient nickel(ii)-catalyzed transfer dehydrogenation oxidation of alcohols is reported that relies on cyclohexanone as the formal oxidant and does not require the use of an external base. The synthetic utility of this protocol is demonstratedviathe facile oxidation of structurally complicated natural products.
- Ye, Danfeng,Liu, Zhiyuan,Sessler, Jonathan L.,Lei, Chuanhu
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supporting information
p. 11811 - 11814
(2020/10/13)
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- Synthesis and Immobilization of Metal Nanoparticles Using Photoactive Polymer-Decorated Zeolite L Crystals and Their Application in Catalysis
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A facile route to generate Au and Pd nanoparticles (NPs) on zeolite L crystals decorated with photoactive polymer brushes is described. The polymers used in this approach serve a dual role: Upon irradiation with UV light, they release highly reducing ketyl radicals in a Norrish-Type-I reaction. These radicals serve as one electron donors to reduce metal salts to the corresponding metal NPs. At the same time the polymer shell stabilizes the in situ generated metal NPs. It is shown that the zeolite-polymer-NP composites can be used as recyclable catalysts for the oxidation of benzylic alcohols to aldehydes and the stereoselective semihydrogenation of alkynes to Z-alkenes. The polymer shell in these hybrid catalysts protects the NPs from aggregation and also alters their catalytic properties. (Figure presented.).
- Wissing, Maren,Niehues, Maximilian,Ravoo, Bart Jan,Studer, Armido
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supporting information
p. 2245 - 2253
(2020/05/05)
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- Acceptorless and Base-Free Dehydrogenation of Alcohols Mediated by a Dipyridylamine-Iridium(III) Catalyst
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Several dipyridylamine-IrIII and dipyridylamine-RuII complexes have been evaluated in the acceptorless dehydrogenation of alcohols in the absence of base additives. Iridium catalysts were found superior to ruthenium complexes, and the nature of the bridging nitrogen in dipyridylamine ligands was also evidenced as a key parameter. Catalytic reactions were conducted in toluene, but more sustainable solvents such as anisole and p-cymene were found suitable for this transformation.
- Bruneau, Christian,Fischmeister, Cédric,Guo, Liwei,Jayaprakash, Harikrishnan,Wang, Shengdong
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- Scalable Aerobic Oxidation of Alcohols Using Catalytic DDQ/HNO3
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A selective, practical, and scalable aerobic oxidation of alcohols is described that uses catalytic amounts of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and HNO3, with molecular oxygen serving as the terminal oxidant. The method was successfully applied to the oxidation of a wide range of benzylic, propargylic, and allylic alcohols, including two natural products, namely, carveol and podophyllotoxin. The conditions are also applicable to the selective oxidative deprotection of p-methoxybenzyl ethers.
- Arseniyadis, Stellios,Clavier, Louis,Copin, Chloé,Fournier, Jean,Giffard, Jean-Fran?ois,Jean, Alexandre,Katsina, Tania,Macedo Portela Da Silva, Nayane,Tamion, Rodolphe
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supporting information
p. 856 - 860
(2020/07/14)
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- 2-Bromoanthraquinone as a highly efficient photocatalyst for the oxidation ofsec-aromatic alcohols: experimental and DFT study
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Anthraquinones are recognized as high efficiency photocatalysts which can perform various redox reactions in aqueous or organic phases. We have experimentally proven that 2-BrAQ can undergo hydrogen transfer with an alpha-aromatic alcohol under light conditions, thereby efficiently oxidizing the aromatic alcohol to the corresponding product. The yield of 1-phenethanol to acetophenone can reach more than 96%. In subsequent catalyst screening experiments, it was found that the electronegativity of the substituent at the 2 position of the anthraquinone ring and the acidity of the solvent affect the photocatalytic activity of anthraquinones. After using various aromatic alcohol substrates, 2-BrAQ showed good conversion and selectivity for most aromatic alcohols, but showed C-C bond cleavage and low selectivity with non-α-position aromatic alcohols. In order to explore the mechanism of the redox reaction of 2-BrAQ in acetonitrile solution, the corresponding free radical reaction pathway was proposed and verified by density functional theory (DFT). Focusing on calculations for 2-BrAQ during the reaction and the first-step hydrogen transfer reaction between the 2-BrAQ triplet molecule and the 1-phenylethanol molecule, we recognized the changes that occurred during the reaction and thus have a deeper understanding of the redox reaction of anthraquinone compounds in organic systems.
- Chen, Guanghui,Liao, Shengfu,Liu, Jianguo,Liu, Qiying,Ma, Longlong,Yan, Long
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p. 37014 - 37022
(2020/10/27)
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- Silylium-Ion-Promoted (5+1) Cycloaddition of Aryl-Substituted Vinylcyclopropanes and Hydrosilanes Involving Aryl Migration
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A transition-metal-free (5+1) cycloaddition of aryl-substituted vinylcyclopropanes (VCPs) and hydrosilanes to afford silacyclohexanes is reported. Catalytic amounts of the trityl cation initiate the reaction by hydride abstraction from the hydrosilane, and further progress of the reaction is maintained by self-regeneration of the silylium ions. The new reaction involves a [1,2] migration of an aryl group, eventually furnishing 4- rather than 3-aryl-substituted silacyclohexane derivatives as major products. Various control experiments and quantum-chemical calculations support a mechanistic picture where a silylium ion intramolecularly stabilized by a cyclopropane ring can either undergo a kinetically favored concerted [1,2] aryl migration/ring expansion or engage in a cyclopropane-to-cyclopropane rearrangement.
- Bonetti, Vittorio,He, Tao,Klare, Hendrik F. T.,Oestreich, Martin,Wang, Guoqiang
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supporting information
p. 12186 - 12191
(2020/05/22)
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- B(C6F5)3-Catalyzed Hydrosilylation of Vinylcyclopropanes
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A hydrosilylation of vinylcyclopropanes (VCPs) catalyzed by the strong boron Lewis acid B(C6F5)3 is reported. For the majority of VCPs, little or no ring opening of the cyclopropyl unit is observed. Conversely, for VCPs with bulky R groups, such as ortho-substituted aryl rings or branched alkyl residues, ring opening is the exclusive reaction pathway. This finding is explained by the thwarted hydride delivery to a sterically shielded, β-silicon-stabilized cyclopropylcarbinyl cation intermediate.
- He, Tao,Long, Peng-Wei,Oestreich, Martin
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supporting information
p. 7383 - 7386
(2020/10/12)
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- Vanadium Pyridonate Catalysts: Isolation of Intermediates in the Reductive Coupling of Alcohols
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The reductive coupling of alcohols using vanadium pyridonate catalysts is reported. This attractive approach for C(sp3)-C(sp3) bond formation uses an oxophilic, earth-abundant metal for a catalytic deoxygenation reaction. Several pyridonate complexes of vanadium were synthesized, giving insight into the coordination chemistry of this understudied class of compounds. Isolated intermediates provide experimental mechanistic evidence that complements reported computational mechanistic proposals for the reductive coupling of alcohols. In contrast to previous mononuclear vanadium(V)/vanadium(III)/vanadium(IV) cycles, this pyridonate catalyst system is proposed to proceed by a vanadium(III)/vanadium(IV) cycle involving bimetallic intermediates.
- Griffin, Samuel E.,Schafer, Laurel L.
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supporting information
(2020/04/15)
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- A Bifunctional Iron Nanocomposite Catalyst for Efficient Oxidation of Alkenes to Ketones and 1,2-Diketones
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We herein report the fabrication of a bifunctional iron nanocomposite catalyst, in which two catalytically active sites of Fe-Nx and Fe phosphate, as oxidation and Lewis acid sites, were simultaneously integrated into a hierarchical N,P-dual doped porous carbon. As a bifunctional catalyst, it exhibited high efficiency for direct oxidative cleavage of alkenes into ketones or their oxidation into 1,2-diketones with a broad substrate scope and high functional group tolerance using TBHP as the oxidant in water under mild reaction conditions. Furthermore, it could be easily recovered for successive recycling without appreciable loss of activity. Mechanistic studies disclose that the direct oxidation of alkenes proceeds via the formation of an epoxide as intermediate followed by either acid-catalyzed Meinwald rearrangement to give ketones with one carbon shorter or nucleophilic ring-opening to generate 1,2-diketones in a cascade manner. This study not only opens up a fancy pathway in the rational design of Fe-N-C catalysts but also offers a simple and efficient method for accessing industrially important ketones and 1,2-diketones from alkenes in a cost-effective and environmentally benign fashion.
- Ma, Zhiming,Ren, Peng,Song, Tao,Xiao, Jianliang,Yang, Yong,Yuan, Youzhu
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p. 4617 - 4629
(2020/05/19)
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- Iron-Catalyzed Cleavage Reaction of Keto Acids with Aliphatic Aldehydes for the Synthesis of Ketones and Ketone Esters
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The radical–radical coupling reaction is an important synthetic strategy. In this study, the iron-catalyzed radical–radical cross-coupling reaction based on the decarboxylation of keto acids and decarbonylation of aliphatic aldehydes to obtain valuable aryl ketones is reported for the first time. Remarkably, when tertiary aldehydes were used as carbonyl sources, ketone esters were selectively obtained instead of ketones. The gram-scale preparation of aryl ketone through this strategy was easily achieved by using only 3 mol % of the iron catalyst. As a proof-of-concept, the bioactive molecule flurprimidol was synthesized in two steps by using this strategy.
- Zhou, Fangyuan,Li, Lesong,Lin, Kao,Zhang, Feng,Deng, Guo-Jun,Gong, Hang
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supporting information
p. 4246 - 4250
(2020/03/11)
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- Method for preparing aryl ketone based on iron-catalyzed free radical-free radical coupling reaction such as ketonic acid decarboxylation and fatty aldehyde de-carbonylation
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The invention discloses a method for preparing an aryl ketone derivative based on a free radical-free radical cross-coupling reaction such as ketonic acid decarboxylation and fatty aldehyde de-carbonylation. The method comprises the following steps: reacting aryl-substituted ketonic acid with fatty aldehyde under the catalytic action of ferric triacetylacetonate to generate an aryl ketone derivative; the gram-grade reaction can be realized by the method only by using 3mol% of an iron catalyst; and the method has the advantages of no need of consumption of a large amount of a Lewis acid catalyst or a stoichiometric organic metal reagent, mild reaction conditions, one-step reaction, few by-products, wide substrate application range and scalable reaction, and overcomes the defects of large catalyst consumption, insufficient functional group tolerance, many by-products and the like in the prior art.
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Paragraph 0037-0039
(2020/05/05)
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- Catalytic Oxidative Cleavage Reactions of Arylalkenes by tert-Butyl Hydroperoxide - A Mechanistic Assessment
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Oxidative cleavage reactions of arylalkenes by tert-butyl hydroperoxide that occur by free radical processes provide access to carboxylic acid or ketone products. However, the pathway to these cleavage products is complex, initiated by regioselective oxygen radical addition to the carbon-carbon double bond. Subsequent reactions of the initially formed benzyl radical lead eventually to carbon-carbon cleavage. Thorough investigations of these reactions have identified numerous reaction intermediates that are on the pathways to final product formation, and they have identified a new synthetic methodology for the synthesis of peroxy radical addition-induced hydroperoxide formation.
- Su, Yong-Liang,De Angelis, Luca,Tram, Linh,Yu, Yang,Doyle, Michael P.
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p. 3728 - 3741
(2020/03/23)
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- 1,2-Diethoxyethane catalyzed oxidative cleavage of gem-disubstituted aromatic alkenes to ketones under minimal solvent conditions
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Aerobic oxidation using pure dioxygen gas as the oxidant has attracted much attention, but its application in synthetic chemistry has been significantly hampered by the complexity of catalytic system and potential risk of high-energy dioxygen gas. By employing 1,2-diethoxyethane as a catalyst and ambient air as an oxidant, an efficient protocol for the construction of various aryl-alkyl and diaryl ketones through oxidative cleavage of gem-disubstituted aromatic alkenes under minimal solvent conditions has been achieved.
- Liu, Kai-Jian,Deng, Ji-Hui,Zeng, Tang-Yu,Chen, Xin-Jie,Huang, Ying,Cao, Zhong,Lin, Ying-Wu,He, Wei-Min
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supporting information
p. 1868 - 1872
(2020/01/31)
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- Sodium Hypochlorite Pentahydrate as a Reagent for the Cleavage of trans-Cyclic Glycols
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Sodium hypochlorite pentahydrate (NaOCl·5H2O) can be used toward the efficient glycol cleavage of trans-cyclic glycols, which are generally resistant to this transformation. Interestingly, the reaction of cis-cyclic glycols with NaOCl·5H2O is slower than that observed for the corresponding trans-isomer. This trans selectivity is in sharp contrast to traditional oxidants used for glycol cleavage. Acyclic glycols can also react efficiently with NaOCl·5H2O to form their corresponding carbonyl compounds in high yield.
- Kirihara, Masayuki,Osugi, Rie,Saito, Katsuya,Adachi, Kouta,Yamazaki, Kento,Matsushima, Ryoji,Kimura, Yoshikazu
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p. 8330 - 8336
(2019/06/24)
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- Aerobic oxidation of alcohols with air catalyzed by decacarbonyldimanganese
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The oxidation of alcohols to carbonyl compounds using air as the terminal oxidant is highly desirable. As described in previous reports, the abstraction of α-H of the alcohol is the most important step, and it typically requires not only a metal catalyst but also complex ligands, co-catalysts and bases. Herein, we report a practical and efficient method for the oxidation of primary alcohols, secondary alcohols, 1,2-diols, 1,2-amino alcohols, and other α-functionalized alcohols using a commercially available catalyst, Mn2(CO)10, and no additives. Preliminary mechanistic studies indicated that an alkoxyl radical intermediate existed in our system, and a plausible mechanism consistent with the experimental results and literature was proposed.
- Meng, Shan-Shui,Lin, Li-Rong,Luo, Xiang,Lv, Hao-Jun,Zhao, Jun-Ling,Chan, Albert S. C.
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supporting information
p. 6187 - 6193
(2019/11/20)
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- Iron–PNP-Pincer-Catalyzed Transfer Dehydrogenation of Secondary Alcohols
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The well-defined iron PNP pincer complex catalyst [Fe(H)(BH4)(CO)(HN{CH2CH2P(iPr)2}2] was used for the catalytic dehydrogenation of secondary alcohols to give the corresponding ketones. Using acetone as inexpensive hydrogen acceptor enables the oxidation with good to excellent yields. DFT computations indicate an outer-sphere mechanism and support the importance of an acceptor to achieve this transformation under milder conditions.
- Budweg, Svenja,Wei, Zhihong,Jiao, Haijun,Junge, Kathrin,Beller, Matthias
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- Metal-ligand cooperativity in a ruthenium(II) complex of bis-azoaromatic ligand for catalytic dehydrogenation of alcohols
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Herein a new Ru-phosphine complex (1) with molecular formula [RuL(PPh3)Cl2] is reported where L is a redox active pincer ligand 2,6-bis(phenylazo)pyridine. The isolated complex has been characterized by usual spectroscopic techniques including single crystal X-ray crystallographic analysis. Complex 1 efficiently catalyzes aerobic oxidation of a wide range of primary and secondary benzylic, allylic, heterocyclic, alicyclic alcohols under mild conditions and is found to be superior over several other Ru (0, +2 and +3), Ru-H and Ru-PPh3 catalysts. Mechanistic studies indicate that a transient Ru-H intermediate is formed in the catalytic cycle which gets switched into a Ru-hydrazo intermediate via hydrogen-walking mechanism. The catalyst is regenerated by aerial oxidation producing H2O2 as a by-product.
- Saha, Tanushri,Pramanick, Rajib,Sengupta, Debabrata,Goswami, Sreebrata
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p. 160 - 166
(2018/09/29)
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- A facile approach to constructing Pd@PCN-Se nano-composite catalysts for selective alcohol oxidation reactions
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By using selenium as the structure-directing agent, Se-incorporated polymeric carbon nitride (PCN-Se) was prepared for the first time and could be used as a superexcellent support for Pd nanoparticles (NPs). A trace amount of Se dopant (0.01 wt%) was found to play an unexpectedly vital role in increasing the materials' surface area and total mesoporous volume by 4.5 and 2 times respectively, so the Pd@PCN-Se catalyst might contain even more active sites than its simple PCN and Pd@PCN counterparts, and a strong interaction between Se(0) and Pd(ii) was also built-in, affording a dramatically improved catalytic activity as well as good recycling stability in selective catalytic alcohol oxidation reactions.
- Cao, Kuanhong,Deng, Xin,Chen, Tian,Zhang, Qitao,Yu, Lei
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supporting information
p. 10918 - 10923
(2019/05/17)
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- Selective oxidation of exogenous substrates by a bis-Cu(III) bis-oxide complex: Mechanism and scope
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Cu(III)2(μ-O)2 bis-oxides (O) form spontaneously by direct oxygenation of nitrogen-chelated Cu(I) species and constitute a diverse class of versatile 2e?/2H+ oxidants, but while these species have attracted attention as biomimetic models for dinuclear Cu enzymes, reactivity is typically limited to intramolecular ligand oxidation, and systems exhibiting synthetically useful reactivity with exogenous substrates are limited. OTMPD (TMPD = N1, N1, N3, N3-tetramethylpropane-1,3-diamine) presents an exception, readily oxidizing a diverse array of exogenous substrates, including primary alcohols and amines selectively over their secondary counterparts in good yields. Mechanistic and DFT analyses suggest substrate oxidation proceeds through initial axial coordination, followed by rate-limiting rotation to position the substrate in the Cu(III) equatorial plane, whereupon rapid deprotonation and oxidation by net hydride transfer occurs. Together, the results suggest the selectivity and broad substrate scope unique to OTMPD are best attributed to the combination of ligand flexibility, limited steric demands, and ligand oxidative stability. In keeping with the absence of rate-limiting C–H scission, OTMPD exhibits a marked insensitivity to the strength of the substrate Cα–H bond, readily oxidizing benzyl alcohol and 1-octanol at near identical rates.
- Large, Tao A.G.,Mahadevan, Viswanath,Keown, William,Stack, T. Daniel P.
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p. 782 - 792
(2019/01/03)
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- Transfer-dehydrogenation of secondary alcohols catalyzed by manganese NNN-pincer complexes
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Novel catalytic systems based on pentacarbonylmanganese bromide and stable NNN-pincer ligands are presented for the transfer-dehydrogenation of secondary alcohols to give the corresponding ketones in good to excellent isolated yields. Best results are obtained using di-picolylamine derivatives as ligands and acetone as an inexpensive hydrogen acceptor. Besides high activity for benzylic substrates, aliphatic alcohols, as well as steroid derivatives, are readily oxidized in the presence of the optimal phosphorus-free catalyst.
- Budweg, Svenja,Junge, Kathrin,Beller, Matthias
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supporting information
p. 14143 - 14146
(2019/12/02)
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- Electrochemical C-H oxygenation and alcohol dehydrogenation involving Fe-oxo species using water as the oxygen source
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High-valent iron-oxo complexes are key intermediates in C-H functionalization reactions. Herein, we report the generation of a (TAML)Fe-oxo species (TAML = tetraamido macrocyclic ligand) via electrochemical proton-coupled oxidation of the corresponding (TAML)FeIII-OH2 complex. Cyclic voltammetry (CV) and spectroelectrochemical studies are used to elucidate the relevant (TAML)Fe redox processes and determine the predominant (TAML)Fe species present in solution during bulk electrolysis. Evidence for iron(iv) and iron(v) species is presented, and these species are used in the electrochemical oxygenation of benzylic C-H bonds and dehydrogenation of alcohols to ketones.
- Das, Amit,Nutting, Jordan E.,Stahl, Shannon S.
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p. 7542 - 7548
(2019/08/20)
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- Generation of Halomethyl Radicals by Halogen Atom Abstraction and Their Addition Reactions with Alkenes
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α-Aminoradicals undergo halogen atom abstraction to form halomethyl radicals in reactions initiated by the combination of tert-butyl hydroperoxide, aliphatic trialkylamine, halocarbon, and copper(I) iodide. The formation of the α-aminoradical circumvents preferential hydrogen atom transfer in favor of halogen atom transfer, thereby releasing the halomethyl radical for addition to alkenes. The resulting radical addition products add the tert-butylperoxy group to form α-peroxy-β,β-dichloropropylbenzene products that are convertible to their corresponding β,β-dichloro-alcohols and to novel pyridine derivatives. Computational analysis clearly explains the deviation from traditional HAT of chloroform and also establishes formal oxidative addition/reductive elimination as the lowest energy pathway.
- Neff, Robynne K.,Su, Yong-Liang,Liu, Siqi,Rosado, Melina,Zhang, Xinhao,Doyle, Michael P.
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supporting information
p. 16643 - 16650
(2019/11/13)
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- Arylation of Aldehydes to Directly Form Ketones via Tandem Nickel Catalysis
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A nickel-catalyzed arylation of both aliphatic and aromatic aldehydes proceeds with air-stable (hetero)arylboronic acids, with an exceptionally wide substrate scope. The neutral condition tolerates acidic hydrogen and sensitive polar groups and also preserves α-stereocenters of some chiral aldehydes. Interestingly, this nickel(0) catalysis does not follow common 1,2-insertion of arylmetal species to aldehydes and β-hydrogen elimination.
- Lei, Chuanhu,Zhu, Daoyong,Tangcueco, Vicente Iii Tiu,Zhou, Jianrong Steve
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supporting information
p. 5817 - 5822
(2019/08/26)
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- Ketone Synthesis by a Nickel-Catalyzed Dehydrogenative Cross-Coupling of Primary Alcohols
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An intermolecular coupling of primary alcohols and organotriflates has been developed to provide ketones by the action of a Ni(0) catalyst. This oxidative transformation is proposed to occur by the union of three distinct catalytic cycles. Two competitive oxidation processes generate aldehyde in situ via hydrogen transfer oxidation or (pseudo)dehalogenation pathways. As aldehyde forms, a Ni-catalyzed carbonyl-Heck process enables formation of the key carbon-carbon bond. The utility of this rare alcohol to ketone transformation is demonstrated through the synthesis of diverse complex and bioactive molecules.
- Verheyen, Thomas,Van Turnhout, Lars,Vandavasi, Jaya Kishore,Isbrandt, Eric S.,De Borggraeve, Wim M.,Newman, Stephen G.
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supporting information
(2019/05/08)
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- Ketone Synthesis by a Nickel-Catalyzed Dehydrogenative Cross-Coupling of Primary Alcohols
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An intermolecular coupling of primary alcohols and organotriflates has been developed to provide ketones by the action of a Ni(0) catalyst. This oxidative transformation is proposed to occur by the union of three distinct catalytic cycles. Two competitive oxidation processes generate aldehyde in situ via hydrogen transfer oxidation or (pseudo)dehalogenation pathways. As aldehyde forms, a Ni-catalyzed carbonyl-Heck process enables formation of the key carbon-carbon bond. The utility of this rare alcohol to ketone transformation is demonstrated through the synthesis of diverse complex and bioactive molecules.
- Verheyen, Thomas,Van Turnhout, Lars,Vandavasi, Jaya Kishore,Isbrandt, Eric S.,De Borggraeve, Wim M.,Newman, Stephen G.
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supporting information
p. 6869 - 6874
(2019/05/10)
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- Mild Cu-Catalyzed Oxidation of Benzylic Boronic Esters to Ketones
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The oxidation of benzylic boronic esters directly to the ketone is reported. This mild Cu-catalyzed method uses an ambient atmosphere of air as the terminal oxidant and is notably chemoselective. Oxidation of the C-B bond occurs selectively, even in the presence of unprotected alcohols. Initial investigation suggests the reaction proceeds through an alkylboron to Cu transmetalation, peroxide formation, and rearrangement to give the carbonyl.
- Grayson, James D.,Partridge, Benjamin M.
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p. 4296 - 4301
(2019/05/14)
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- Effects of Ancillary Ligands on Redox and Chemical Properties of Ruthenium Coordinated Azoaromatic Pincer
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In this work, the effect of the electronically different ancillary ligands on the overall properties of the RuIIL moiety (L = 2,6-bis(phenylazo)pyridine) in heteroleptic complexes of general formula [RuLQCl]0/+ was investigated. Four different ancillary ligands (Q) with different electronic effects were used to prepare the heteroleptic compounds from the precursor complex, [RuL(CH3CN)Cl2] (1); Q = pcp: 2-(4-chloro-phenylazo)pyridine (strong π-acceptor), [2]+ bpy: 2,2′-bipyridyl (moderate π-acceptor), [3]+ acac-: acetylacetonate (strong σ-donor), 4; and DTBCat2-: 3,5-di-tert-butyl catecholate (strong π-donor), 5. The complexes [2]+, [3]+, 4, and 5 were fully characterized and structurally identified. The electronic structures of these complexes along with their redox partners were elucidated by using a host of physical measurements: nuclear magnetic resonance, cyclic voltammetry, electronic paramagnetic resonance, UV-vis-NIR spectroscopy, and density functional theory. The studies revealed significant effects of the coligands on azo bond lengths of the RuL moiety and their redox behavior. Aerobic alcohol oxidation reactions using these Ru complexes as catalysts were scrutinized. It was found that the catalytic efficiency is primarily controlled by the electronic effect of the coligand. Accordingly, the complex [2]+ (containing a strong π-acceptor coligand, pcp) brings about oxidation efficiently, producing 86% of benzaldehyde. In comparison, however, the complexes 4 and 5 (containing electron donating coligand) furnished only 15-20% of benzaldehyde under identical reaction conditions. Investigations of the reaction mechanism suggest that an unstable Ru-H species is formed, which is transformed to a Ru-hydrazo intermediate by H-walking as reported by Hall et al. (J. Am. Chem. Soc., 2015, 137, 12330). Aerial O2 regenerates the catalyst via oxidation of the hydrazo intermediate.
- Rath, Santi Prasad,Sengupta, Debabrata,Ghosh, Pradip,Bhattacharjee, Rameswar,Chakraborty, Mou,Samanta, Subhas,Datta, Ayan,Goswami, Sreebrata
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p. 11995 - 12009
(2018/09/25)
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- Gold-catalyzed conversion of lignin to low molecular weight aromatics
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A heterogeneous catalyst system, employing Au nanoparticles (NPs) and Li-Al (1:2) layered double hydroxide (LDH) as support, showed excellent activity in aerobic oxidation of the benzylic alcohol group in β-O-4 linked lignin model dimers to the corresponding carbonyl products using molecular oxygen under atmospheric pressure. The synergistic effect between Au NPs and the basic Li-Al LDH support induces further reaction of the oxidized model compounds, facilitating facile cleavage of the β-O-4 linkage. Extension to oxidation of γ-valerolactone (GVL) extracted lignin and kraft lignin using Au/Li-Al LDH under similar conditions produced a range of aromatic monomers in high yield. Hydrolysis of the Au/Li-Al LDH oxidized lignin was found to increase the degree of lignin depolymerization, with monomer yields reaching 40% for GVL extracted lignin. Based on these results, the Au/Li-Al LDH + O2 catalyst system shows potential to be an environmentally friendly means of depolymerizing lignin to low molecular weight aromatics under mild conditions.
- Song, Yang,Mobley, Justin K.,Motagamwala, Ali Hussain,Isaacs, Mark,Dumesic, James A.,Ralph, John,Lee, Adam F.,Wilson, Karen,Crocker, Mark
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p. 8127 - 8133
(2018/11/20)
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- The Use of Calcium Carbide as Acetylene Source in a Three-Component Coupling with ω-Chlorinated Ketones and Primary Amines
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Calcium carbide was used in a CuI-catalysed three-component coupling with ω-chlorinated ketones and primary amines to generate terminal 2-alkynyl-N-heterocycles. The formation of an imine and the subsequent intramolecular substitution results in an active electrophilic iminium species, which can be alkynylated by in situ formed copper acetylide. A number of aliphatic primary (functionalised) amines and aliphatic or aromatic alkynes together with different alkyl- or aryl-substituted γ- or δ-chloroketones could be used. Simple acid–base workup instead of column chromatography can be applied to obtain the resulting 2-alkynylpyrrolidines and 2-alkynylpiperidines.
- Van Beek, Wim E.,Gadde, Karthik,Tehrani, Kourosch Abbaspour
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supporting information
p. 16645 - 16651
(2018/10/24)
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- Mild Ring Contractions of Cyclobutanols to Cyclopropyl Ketones via Hypervalent Iodine Oxidation
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An iodine-mediated oxidative ring contraction of cyclobutanols has been developed. The reaction allows the synthesis of a wide range of aryl cyclopropyl ketones under mild and eco-friendly conditions. A variety of functional groups including aromatic or alkyl halides, ethers, esters, ketones, alkenes, and even aldehydes are nicely tolerated in the reaction. This is in contrast with traditional synthetic approaches for which poor functional group tolerance is often a problem. The practicality of the method is also highlighted by the tunability of iodine oxidation system. Specifically, combining the iodine(III) reagent with an appropriate base allows the reaction to accommodate a range of challenging electron-rich arene substrates. The facile scalability of this reaction is also exhibited herein. (Figure presented.).
- Sun, Yan,Huang, Xin,Li, Xiaojin,Luo, Fan,Zhang, Lei,Chen, Mengyuan,Zheng, Shiya,Peng, Bo
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supporting information
p. 1082 - 1087
(2018/01/27)
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- Thiyl radical promoted chemo- and regioselective oxidation of CC bonds using molecular oxygen: Via iron catalysis
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The first example of the thiyl radical promoted ligand-free iron-catalyzed oxidative cleavage of alkenes using molecular oxygen (1 atm) has been developed. The reaction proceeds under mild reaction conditions with high efficiency and high chemo- and regioselectivity. It features a broad substrate scope and excellent functional group compatibility, enabling facile access to valuable molecules for application in medicinal chemistry. Preliminary mechanistic studies reveal that a vital intermediate dioxetane might be involved in the reaction and a thiyl radical plays a synergistic role in facilitating the selective oxidation of the CC bond.
- Xiong, Baojian,Zeng, Xiaoqin,Geng, Shasha,Chen, Shuo,He, Yun,Feng, Zhang
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supporting information
p. 4521 - 4527
(2018/10/17)
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- Alcohol Oxidations Using Reduced Polyoxovanadates
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A full account of our recently communicated room temperature alcohol oxidation using reduced polyoxovanadates (r-POVs) is presented. Extensive optimizations revealed optimal conditions employing 0.02 equiv. of r-POV catalyst Cs5(V14As8O42Cl), 5 equiv. tert-butyl hydrogen peroxide (tBuOOH) as the terminal co-oxidant, in an acetone solvent for the quantitative oxidation of aryl-substituted secondary alcohols to their ketone products. The substrate scope tolerates most aryl substituted secondary alcohols in good to quantitative yields while alkyl secondary and primary activated alcohols were sluggish in comparison under similar conditions. Catalyst recyclability was successful on a 1.0?mmol scale of starting alcohol 1-phenylethanol. The oxidation was also successfully promoted by the VIV/VV mixed valent polyoxovanadate (POV) Cs11Na3Cl5(V15O36Cl). Finally, a third POV, Cs2.64(V5O9)(AsO4)2, was investigated for catalytic activity using our established reaction protocol, but proved ineffective as compared to the other two r-POV catalysts. This study expands the field of POM-mediated alcohol oxidations to include underexplored r-POV catalysts. While our catalysts do not supplant the best catalysts known for the transformation, their study may inform the development of other novel oxidative transformations mediated by r-POVs.
- Campbell, McKenzie L.,Sulejmanovic, Dino,Schiller, Jacqueline B.,Turner, Emily M.,Hwu, Shiou-Jyh,Whitehead, Daniel C.
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- Reactions catalyzed by a binuclear copper complex: Selective oxidation of alkenes to carbonyls with O2
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Terminal alkenes were selectively cleaved into ketones and aldehydes catalyzed by a binuclear copper catalyst bearing a simple salicylate ligand with O2 as the oxidant. The reaction was carried out under an atmosphere of O2 (balloon) with 0.5 mol% of catalyst and could be performed on a gram scale, providing a convenient and practical method for the cleavage of terminal alkenes into carbonyl compounds.
- Liu, Yuxia,Xue, Dong,Li, Chaoqun,Xiao, Jianliang,Wang, Chao
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p. 5510 - 5514
(2017/12/08)
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- Organoselenium-Catalyzed Oxidative C=C Bond Cleavage: A Relatively Green Oxidation of Alkenes into Carbonyl Compounds with Hydrogen Peroxide
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A relatively green oxidative C=C bond cleavage of alkenes was achieved by organoselenium-catalyzed alkene oxidation reaction in ethanol with hydrogen peroxide, affording carbonyl compounds under relatively mild conditions. It is a new reaction style for the organoselenium-catalyzed oxidation of alkenes and largely contributes to the growing field of organoselenium catalysis.
- Wang, Tingting,Jing, Xiaobi,Chen, Chao,Yu, Lei
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p. 9342 - 9349
(2017/09/23)
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- Dioxygen Activation by a Hexagonal SrMnO3 Perovskite Catalyst for Aerobic Liquid-Phase Oxidation
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Heterogeneous catalysts, which allow a reductive activation of dioxygen (O2) under mild reaction conditions, are promising candidates for highly efficient aerobic oxidation. An effective hexagonal SrMnO3 (SMO) perovskite catalyst for liquid-phase selective oxidation with O2 was successfully synthesized by the polymerized complex method. The activity of SMO for the aerobic oxidation of alcohols was higher than those of typical manganese oxide-based catalysts and was heterogeneous, so that the recovered catalyst could be reused without heat treatment under oxidative conditions while keeping its high catalytic performance. The reversible reaction on the surface Mn species on SMO with O2 leads to the formation of Mn–superoxo species, which catalyze the selective oxidative transformation of various types of organic substrates into the desired oxygenated or dehydrogenated products.
- Kawasaki, Shuma,Kamata, Keigo,Hara, Michikazu
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p. 3247 - 3253
(2016/10/24)
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- Simple and Efficient Ruthenium-Catalyzed Oxidation of Primary Alcohols with Molecular Oxygen
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Oxidative transformations utilizing molecular oxygen (O2) as the stoichiometric oxidant are of paramount importance in organic synthesis from ecological and economical perspectives. Alcohol oxidation reactions that employ O2are scarce in homogeneous catalysis and the efficacy of such systems has been constrained by limited substrate scope (most involve secondary alcohol oxidation) or practical factors, such as the need for an excess of base or an additive. Catalytic systems employing O2as the “primary” oxidant, in the absence of any additive, are rare. A solution to this longstanding issue is offered by the development of an efficient ruthenium-catalyzed oxidation protocol, which enables smooth oxidation of a wide variety of primary, as well as secondary benzylic, allylic, heterocyclic, and aliphatic, alcohols with molecular oxygen as the primary oxidant and without any base or hydrogen- or electron-transfer agents. Most importantly, a high degree of selectivity during alcohol oxidation has been predicted for complex settings. Preliminary mechanistic studies including18O labeling established the in situ formation of an oxo–ruthenium intermediate as the active catalytic species in the cycle and involvement of a two-electron hydride transfer in the rate-limiting step.
- Ray, Ritwika,Chandra, Shubhadeep,Maiti, Debabrata,Lahiri, Goutam Kumar
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supporting information
p. 8814 - 8822
(2016/07/06)
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- Acceptorless dehydrogenation and aerobic oxidation of alcohols with a reusable binuclear rhodium(II) catalyst in water
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A water-soluble binuclear rhodium(ii) complex was found to be an efficient catalyst for both acceptorless dehydrogenation and aerobic oxidation of alcohols under air to produce carboxylic acids or ketones in water. The catalyst is highly efficient with substrate/catalyst ratios up to 5 × 103 being feasible, and could be recycled 19 times without significant loss of activity.
- Wang, Xuewei,Wang, Chao,Liu, Yuxuan,Xiao, Jianliang
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supporting information
p. 4605 - 4610
(2016/09/04)
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