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Catalytic oxyfunctionalization of saturated hydrocarbons by non-heme oxo-bridged diiron(III) complexes: role of acetic acid on oxidation reaction
Oxo-bridged diiron(III) complexes [Fe2O(L1)2(H2O)2](ClO4)4 (1) and [Fe2O(L2)2(H2O)2](ClO4)4 (2), where L1 and L2 are tetradentate N-donor N,N′-bis(2-pyridylmethyl)-1,2-cyclohexanediamine and N,N′-bis(2-pyridylmethyl)ethane-1,2-diamine respectively, have been isolated as synthetic models of non-heme iron oxygenases and characterized by physicochemical and spectroscopic methods. Both the complexes have been studied as catalysts for the oxyfunctionalization of saturated hydrocarbons using green hydrogen peroxide (H2O2) as oxidant under mild conditions. The selectivity (A/K) and regioselectivity (3°/2°) in oxidative C–H functionalization of alkanes suggests the involvement of metal-based intermediate in the oxygenation reaction. The catalytic efficiency is found to be strongly dependent on the presence of acetic acid. Remarkable increase in conversion and selectivity favoring the formation of alcohols in the oxidation of cyclohexane and cyclooctane and exclusive hydroxylation of adamantane with drastic enhancement of regioselectivity has been achieved by the addition of acetic acid in the presence of H2O2.
Agarwalla, Uday Sankar
p. 583 - 588
(2020)
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Efficient and selective oxidation of hydrocarbons with tert-butyl hydroperoxide catalyzed by oxidovanadium(IV) unsymmetrical Schiff base complex supported on γ-Fe2O3 magnetic nanoparticles
The catalytic activity of an oxidovanadium(IV) unsymmetrical Schiff base complex supported on γ-Fe2O3 magnetic nanoparticles, γ-Fe2O3@[VO(salenac-OH)] in which salenac-OH = [9-(2′,4′-dihydroxyphenyl)-5,8-diaza-4
Samani, Mahnaz,Ardakani, Mehdi Hatefi,Sabet, Mohammad
p. 1481 - 1494
(2022/01/22)

Pyridazine N-Oxides as Photoactivatable Surrogates for Reactive Oxygen Species
A method for the photoinduced evolution of atomic oxygen from pyridazine N-oxides was developed. This underexplored oxygen allotrope mediates arene C-H oxidation within complex, polyfunctional molecules. A water-soluble pyridazine N-oxide was also developed and shown to promote photoinduced DNA cleavage in aqueous solution. Taken together, these studies highlight the utility of pyridazine N-oxides as photoactivatable O(3P) precursors for applications in organic synthesis and chemical biology.
Basistyi, Vitalii S.,Frederich, James H.
supporting information
p. 1907 - 1912
(2022/03/27)

Cu6- And Cu8-Cage Sil- And Germsesquioxanes: Synthetic and Structural Features, Oxidative Rearrangements, and Catalytic Activity
This study reports intriguing features in the self-assembly of cage copper(II) silsesquioxanes in the presence of air. Despite the wide variation of solvates used, a series of prismatic hexanuclear Cu6 cages (1-5) were assembled under mild conditions. In turn, syntheses at higher temperatures are accompanied by side reactions, leading to the oxidation of solvates (methanol, 1-butanol, and tetrahydrofuran). The oxidized solvent derivatives then specifically participate in the formation of copper silsesquioxane cages, allowing the isolation of several unusual Cu8-based (6 and 7) and Cu6-based (8) complexes. When 1,4-dioxane was applied as a reaction medium, deep rearrangements occurred (with a total elimination of silsesquioxane ligands), causing the formation of mononuclear copper(II) compounds bearing oxidized dioxane fragments (9 and 11) or a formate-driven 1D coordination polymer (10). Finally, a "directed"self-assembly of sil- and germsesquioxanes from copper acetate (or formate) resulted in the corresponding acetate (or formate) containing Cu6 cages (12 and 13) that were isolated in high yields. The structures of all of the products 1-13 were established by single-crystal X-ray diffraction, mainly based on the use of synchrotron radiation. Moreover, the catalytic activity of compounds 12 and 13 was evaluated toward the mild homogeneous oxidation of C5-C8 cycloalkanes with hydrogen peroxide to form a mixture of the corresponding cyclic alcohols and ketones.
Astakhov, Grigorii S.,Levitsky, Mikhail M.,Zubavichus, Yan V.,Khrustalev, Victor N.,Titov, Aleksei A.,Dorovatovskii, Pavel V.,Smol'Yakov, Alexander F.,Shubina, Elena S.,Kirillova, Marina V.,Kirillov, Alexander M.,Bilyachenko, Alexey N.
p. 8062 - 8074
(2021/05/26)

Primary Alcohols via Nickel Pentacarboxycyclopentadienyl Diamide Catalyzed Hydrosilylation of Terminal Epoxides
The efficient and regioselective hydrosilylation of epoxides co-catalyzed by a pentacarboxycyclopentadienyl (PCCP) diamide nickel complex and Lewis acid is reported. This method allows for the reductive opening of terminal, monosubstituted epoxides to form unbranched, primary alcohols. A range of substrates including both terminal and nonterminal epoxides are shown to work, and a mechanistic rationale is provided. This work represents the first use of a PCCP derivative as a ligand for transition-metal catalysis.
Lambert, Tristan H.,Steiniger, Keri A.
p. 8013 - 8017
(2021/10/25)

Synthesis of new rhodium(III) complex by benzylic C[sbnd]S bond cleavage of thioether containing NNS donor Schiff base ligand: Investigation of catalytic activity towards transfer hydrogenation of ketones
A new rhodium(III)-triphenylphosphine mixed ligand complex, [Rh(PPh3)(L)Cl2] (1) is synthesized by benzylic C[sbnd]S bond cleavage of L-CH2Ph ligand (where, L-CH2Ph = 2-(benzylthio)-N-(pyridin-2-ylmethylene)aniline). The complex is thoroughly characterized by several spectroscopic techniques. Geometry of the complex is confirmed by single crystal X-ray crystallography. Electronic structure, redox properties, absorption and emission properties of the complex were studied. DFT and TDDFT calculations were carried out to interpret the electronic structure and absorption properties of the complex respectively. The synthesized Rh(III) complex was tested as catalyst towards transfer hydrogenation reaction of ketones in iPrOH and an excellent catalytic conversion was observed under mild conditions.
Biswas, Sujan,Das, Akash,Kumar Manna, Chandan,Kumar Mondal, Tapan,Naskar, Rahul
(2020/11/04)

Efficient oxidation of cycloalkanes with simultaneously increased conversion and selectivity using O2 catalyzed by metalloporphyrins and boosted by Zn(AcO)2: A practical strategy to inhibit the formation of aliphatic diacids
The direct sources of aliphatic acids in cycloalkanes oxidation were investigated, and a strategy to suppress the formation of aliphatic acids was adopted through enhancing the catalytic transformation of oxidation intermediates cycloalkyl hydroperoxides to cycloalkanols by Zn(II) and delaying the emergence of cycloalkanones. Benefitted from the delayed formation of cycloalkanones and suppressed non-selective thermal decomposition of cycloalkyl hydroperoxides, the conversion of cycloalkanes and selectivity towards cycloalkanols and cycloalkanones were increased simultaneously with satisfying tolerance to both of metalloporphyrins and substrates. For cyclohexane, the selectivity towards KA-oil was increased from 80.1% to 96.9% meanwhile the conversion was increased from 3.83 % to 6.53 %, a very competitive conversion level with higher selectivity compared with current industrial process. This protocol is not only a valuable strategy to overcome the problems of low conversion and low selectivity lying in front of current cyclohexane oxidation in industry, but also an important reference to other alkanes oxidation.
Shen, Hai-Min,Wang, Xiong,Ning, Lei,Guo, A-Bing,Deng, Jin-Hui,She, Yuan-Bin
(2020/11/20)

Three metal centers (Co _AOMARKENCODEAMPX0AOA) Cu _AOMARKENCODEAMPX0AOA Method using Zn) 2D MOFs/ultraviolet light to catalyze oxidation of cycloalkane
The invention relates to a three-metal center (Co _AOMARKENCODEAMPX0AOA). Cu _AOMARKENCODEAMPX0AOA The method comprises Zn) 2D MOFs/ultraviolet light catalytic oxidation of cycloalkane to synthesize cycloalkyl alcohol and cycloalkanone, and belongs to the field of industrial catalysis and fine organic synthesis. To the application method, metalloporphyrin three-metal center (Co _AOMARKENCODEAMPX0AOA) is used. Cu _AOMARKENCODEAMPX0AOA Zn) 2D MOFs dispersed in cycloalkane, wherein metalloporphyrin three-metal center (Co _AOMARKENCODEAMPX0AOA) Cu _AOMARKENCODEAMPX0AOA Zn) 2D MOFs mass is 0.01% - 20%, g / mol of the substance of the cycloalkane, and the reaction system is sealed. An oxidant is introduced, the ultraviolet lamp is a light source, and the reaction liquid of the stirring reaction 2.0-24 . 0h. is subjected to post-treatment to obtain the product cycloalkyl alcohol and cycloalkyl ketone. The method provided by the invention has the advantages of low reaction temperature, mild reaction conditions, high reaction efficiency, high selectivity of cycloalkyl alcohol and cycloalkyl ketone, less byproducts and small environmental impact. The invention provides a high efficiency. Available, safe cycloalkanes selectively catalyze the oxidative synthesis of cycloalkyl alcohols and cycloalkyl ketones.
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Paragraph 0028; 0079-0080

(2021/11/06)

Hydroxylation of Unactivated C(sp3)-H Bonds with m-Chloroperbenzoic Acid Catalyzed by an Iron(III) Complex Supported by a Trianionic Planar Tetradentate Ligand
Hydroxylation of cyclohexane with m-chloroperbenzoic acid was examined in the presence of an iron(III) complex supported by a trianionic planar tetradentate ligand. The present reaction system shows a high turnover number of 2750 with a high product selectivity of alcohol (93%). The turnover frequency was 0.51 s-1, and the second-order rate constant (k) for the C-H bond activation of cyclohexane was 1.08 M-1 s-1, which is one of the highest values among the iron complexes in the oxidation of cyclohexane so far reported. The present catalytic system can be adapted to the hydroxylation of substrates having only primary C-H bonds such as 2,2,3,3-tetramethylbutane as well as gaseous alkanes such as butane, propane, and ethane. The involvement of an iron(III) acyl peroxido complex as the reactive species was suggested by spectroscopic measurements of the reaction solution.
Morimoto, Yuma,Hanada, Shinichi,Kamada, Ryusuke,Fukatsu, Arisa,Sugimoto, Hideki,Itoh, Shinobu
supporting information
p. 7641 - 7649
(2021/02/03)

Revisiting Alkane Hydroxylation with m-CPBA (m-Chloroperbenzoic Acid) Catalyzed by Nickel(II) Complexes
Mechanistic studies are performed on the alkane hydroxylation with m-CPBA (m-chloroperbenzoic acid) catalyzed by nickel(II) complexes, NiII(L). In the oxidation of cycloalkanes, NiII(TPA) acts as an efficient catalyst with a high yield and a high alcohol selectivity. In the oxidation of adamantane, the tertiary carbon is predominantly oxidized. The reaction rate shows first-order dependence on [substrate] and [NiII(L)] but is independent on [m-CPBA]; vobs=k2[substrate][NiII(L)]. The reaction exhibited a relatively large kinetic deuterium isotope effect (KIE) of 6.7, demonstrating that the hydrogen atom abstraction is involved in the rate-limiting step of the catalytic cycle. Furthermore, NiII(L) supported by related tetradentate ligands exhibit apparently different catalytic activity, suggesting contribution of the NiII(L) in the catalytic cycle. Based on the kinetic analysis and the significant effects of O2 and CCl4 on the product distribution pattern, possible contributions of (L)NiII?O. and the aroyloxyl radical as the reactive oxidants are discussed.
Itoh, Mayu,Itoh, Shinobu,Kubo, Minoru,Morimoto, Yuma,Shinke, Tomoya,Sugimoto, Hideki,Wada, Takuma,Yanagisawa, Sachiko
p. 14730 - 14737
(2021/09/29)

Chemoselective Cleavage of Si-C(sp3) Bonds in Unactivated Tetraalkylsilanes Using Iodine Tris(trifluoroacetate)
Organosilanes are synthetically useful reagents and precursors in organic chemistry. However, the typical inertness of unactivated Si-C(sp3) bonds under conventional reaction conditions has hampered the application of simple tetraalkylsilanes in organic synthesis. Herein we report the chemoselective cleavage of Si-C(sp3) bonds of unactivated tetraalkylsilanes using iodine tris(trifluoroacetate). The reaction proceeds smoothly under mild conditions (-50 °C to room temperature) and tolerates various polar functional groups, thus enabling subsequent Tamao-Fleming oxidation to provide the corresponding alcohols. NMR experiments and density functional theory calculations on the reaction indicate that the transfer of alkyl groups from Si to the I(III) center and the formation of the Si-O bond proceed concertedly to afford an alkyl-λ3-iodane and silyl trifluoroacetate. The developed method enables the use of unactivated tetraalkylsilanes as highly stable synthetic precursors.
Matsuoka, Keitaro,Komami, Narumi,Kojima, Masahiro,Mita, Tsuyoshi,Suzuki, Kimichi,Maeda, Satoshi,Yoshino, Tatsuhiko,Matsunaga, Shigeki
supporting information
p. 103 - 108
(2021/01/13)

Borane evolution and its application to organic synthesis using the phase-vanishing method
Although borane is a useful reagent, it is difficult to handle. In this study, borane was generated in situ from NaBH4 or nBu4NBH4 with several oxidants using a phase-vanishing (PV) method. The borane generated was directly reacted with alkenes, affording the desired alcohols in good yields after oxidation with H2O2 under basic conditions. The selective reduction of carboxylic acids with the evolved borane was examined. The organoboranes generated by the PV method successfully underwent Suzuki–Miyaura coupling. Using this PV system, reactions with borane can be carried out easily and safely in a common test tube.
Soga, Nene,Yoshiki, Tomo,Sato, Aoi,Kawamoto, Takuji,Ryu, Ilhyong,Matsubara, Hiroshi
supporting information

(2021/03/26)

Time-Dependent Self-Assembly of Copper(II) Coordination Polymers and Tetranuclear Rings: Catalysts for Oxidative Functionalization of Saturated Hydrocarbons
This study describes a time-dependent self-assembly generation of new copper(II) coordination compounds from an aqueous-medium reaction mixture composed of copper(II) nitrate, H3bes biobuffer (N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid), ammonium hydroxide, and benzenecarboxylic acid, namely, 4-methoxybenzoic (Hfmba) or 4-chlorobenzoic (Hfcba) acid. Two products were isolated from each reaction, namely, 1D coordination polymers [Cu3(μ3-OH)2(μ-fmba)2(fmba)2(H2O)2]n (1) or [Cu2(μ-OH)2(μ-fcba)2]n (2) and discrete tetracopper(II) rings [Cu4(μ-Hbes)3(μ-H2bes)(μ-fmba)]·2H2O (3) or [Cu4(μ-Hbes)3(μ-H2bes)(μ-fcba)]·4H2O (4), respectively. These four compounds were obtained as microcrystalline air-stable solids and characterized by standard methods, including the single-crystal X-ray diffraction. The structures of 1 and 2 feature distinct types of metal-organic chains driven by the μ3- or μ-OH- ligands along with the μ-benzenecarboxylate linkers. The structures of 3 and 4 disclose the chairlike Cu4 rings assembled from four μ-bridging and chelating aminoalcoholate ligands along with μ-benzenecarboxylate moieties playing a core-stabilizing role. Catalytic activity of 1-4 was investigated in two model reactions, namely, (a) the mild oxidation of saturated hydrocarbons with hydrogen peroxide to form alcohols and ketones and (b) the mild carboxylation of alkanes with carbon monoxide, water, and peroxodisulfate to generate carboxylic acids. Cyclohexane and propane were used as model cyclic and gaseous alkanes, while the substrate scope also included cyclopentane, cycloheptane, and cyclooctane. Different reaction parameters were investigated, including an effect of the acid cocatalyst and various selectivity parameters. The obtained total product yields (up to 34% based on C3H8 or up to 47% based on C6H12) in the carboxylation of propane and cyclohexane are remarkable taking into account an inertness of these saturated hydrocarbons and low reaction temperatures (50-60 °C). Apart from notable catalytic activity, this study showcases a novel time-dependent synthetic strategy for the self-assembly of two different Cu(II) compounds from the same reaction mixture.
Costa, Ines F. M.,Kirillova, Marina V.,André, Vania,Fernandes, Tiago A.,Kirillov, Alexander M.
supporting information
p. 14491 - 14503
(2021/07/19)

Mild oxidative functionalization of cycloalkanes catalyzed by novel dicopper(II) cores
The search for new transition metal based catalytic systems that are active in the oxidative functionalization of such inert substrates as saturated hydrocarbons continues to be an important research direction in molecular catalysis. In the present study, two new copper(II) coordination compounds, namely a discrete dimer [Cu2(μ-H2tea)2(nfa)2]·2H2O (1) and a 1D coordination polymer [Cu2(μ-H2tea)2(μ-Htma)]n·4nH2O (2) were synthesized and applied as homogeneous catalysts for the mild oxidative functionalization of cycloalkanes (cyclopentane, cyclohexane, cycloheptane, and cyclooctane). Both products 1 and 2 were self-assembled in aqueous medium from copper(II) nitrate, triethanolamine (H3tea), sodium hydroxide, and 2-naphthoic (Hnfa) or trimesic (H3tma) acids, isolated as stable crystalline solids, and fully characterized by standard methods including single-crystal X-ray diffraction. Their structures feature a similar type of dicopper(II) triethanolaminate cores that are decorated by terminal or bridging aromatic carboxylate ligands. Two model catalytic reactions were investigated, namely the oxidation of cycloalkanes by H2O2 to produce cycloalkyl hydroperoxides as intermediate products and then a mixture of cyclic alcohols and ketones as final products, and the carboxylation of cycloalkanes with CO/S2O82?/H2O to form cycloalkanecarboxylic acids as main products. These model reactions undergo under very mild conditions (50?60 °C) and show good efficiency. Substrate scope, selectivity features, and the effects of reaction parameters were investigated and discussed in detail. This study widens the family of multicopper(II) cores capable of catalyzing the oxidative functionalization of saturated hydrocarbons under mild conditions.
Trusau, Kiryl I.,Kirillova, Marina V.,André, Vania,Usevich, Andrew I.,Kirillov, Alexander M.
(2021/02/09)

Pincerlike molybdenum complex and preparation method thereof, catalytic composition and application thereof, and alcohol preparation method
The invention discloses a clamp-type molybdenum complex, a preparation method, a corresponding catalyst composition and application. The method comprises the steps: obtaining 9 molybdenum complexes with different structures through coordination reaction of 2-(substituent ethyl)-(5, 6, 7, 8-tetrahydroquinolyl) amine and a corresponding carbonyl molybdenum metal precursor; and catalyzing a ketone compound transfer hydrogenation reaction through a molybdenum complex to generate 40 alcohol compounds. The preparation method of the molybdenum complex is simple, high in yield and good in stability. For a transfer hydrogenation reaction of ketone, the molybdenum-based catalytic system has high catalytic activity and small molybdenum loading capacity, is used for production of aromatic and aliphatic alcohols, and has the advantages of simple method, small environmental pollution and high yield.
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Paragraph 0134-0140

(2021/08/11)

Regiodivergent Hydroborative Ring Opening of Epoxides via Selective C-O Bond Activation
A magnesium-catalyzed regiodivergent C-O bond cleavage protocol is presented. Readily available magnesium catalysts achieve the selective hydroboration of a wide range of epoxides and oxetanes yielding secondary and tertiary alcohols in excellent yields and regioselectivities. Experimental mechanistic investigations and DFT calculations provide insight into the unexpected regiodivergence and explain the different mechanisms of the C-O bond activation and product formation.
Magre, Marc,Paffenholz, Eva,Maity, Bholanath,Cavallo, Luigi,Rueping, Magnus
supporting information
p. 14286 - 14294
(2020/09/15)

Erbium-Catalyzed Regioselective Isomerization-Cobalt-Catalyzed Transfer Hydrogenation Sequence for the Synthesis of Anti-Markovnikov Alcohols from Epoxides under Mild Conditions
Herein, we report an efficient isomerization-transfer hydrogenation reaction sequence based on a cobalt pincer catalyst (1 mol %), which allows the synthesis of a series of anti-Markovnikov alcohols from terminal and internal epoxides under mild reaction conditions (≤55 °C, 8 h) at low catalyst loading. The reaction proceeds by Lewis acid (3 mol % Er(OTf)3)-catalyzed epoxide isomerization and subsequent cobalt-catalyzed transfer hydrogenation using ammonia borane as the hydrogen source. The general applicability of this methodology is highlighted by the synthesis of 43 alcohols from epoxides. A variety of terminal (23 examples) and 1,2-disubstituted internal epoxides (14 examples) bearing different functional groups are converted to the desired anti-Markovnikov alcohols in excellent selectivity and yields of up to 98%. For selected examples, it is shown that the reaction can be performed on a preparative scale up to 50 mmol. Notably, the isomerization step proceeds via the most stable carbocation. Thus, the regiochemistry is controlled by stereoelectronic effects. As a result, in some cases, rearrangement of the carbon framework is observed when tri-and tetra-substituted epoxides (6 examples) are converted. A variety of functional groups are tolerated under the reaction conditions even though aldehydes and ketones are also reduced to the respective alcohols under the reaction conditions. Mechanistic studies and control experiments were used to investigate the role of the Lewis acid in the reaction. Besides acting as the catalyst for the epoxide isomerization, the Lewis acid was found to facilitate the dehydrogenation of the hydrogen donor, which enhances the rate of the transfer hydrogenation step. These experiments additionally indicate the direct transfer of hydrogen from the amine borane in the reduction step.
Liu, Xin,Longwitz, Lars,Spiegelberg, Brian,T?njes, Jan,Beweries, Torsten,Werner, Thomas
p. 13659 - 13667
(2020/11/30)

Efficient Transfer Hydrogenation of Ketones using Methanol as Liquid Organic Hydrogen Carrier
Herein, we demonstrate an efficient protocol for transfer hydrogenation of ketones using methanol as practical and useful liquid organic hydrogen carrier (LOHC) under Ir(III) catalysis. Various ketones, including electron-rich/electron-poor aromatic ketones, heteroaromatic and aliphatic ketones, have been efficiently reduced into their corresponding alcohols. Chemoselective reduction of ketones was established in the presence of various other reducible functional groups under mild conditions.
Garg, Nidhi,Paira, Soumen,Sundararaju, Basker
p. 3472 - 3476
(2020/05/29)

Synthesis of luminescent rhodium(III) cyclometalated complex by sp2(C)–S bond activation: Application as catalyst in transfer hydrogenation of ketones and live cell imaging
A new fluorescent Rh(III) cyclometalated complex, [Rh(PPh3)2(L)Cl] (1) is synthesized via sp2(C)–S bond activation of a thioether containing azo-phenol ligand (L-SCH2CH3). The pseudo octahedral geometry around rhodium is confirmed by single crystal X-ray diffraction method. Cyclic voltammogram of the complex exhibits a quasi-reversible oxidation couple with E1/2 of 0.74 V (ΔE = 100 mV) along with a quasi-reversible reduction couple (E1/2 = ?1.18 V, ΔE = 130 mV) in acetonitrile. The complex exhibits low energy emission band at 682 nm with emission quantum yield (? = 0.103) upon excitation at 583 nm. Cytotoxicity of the complex is studied by MTT method with human breast cancer cell lines and IC50 value is found to 18.5 μM. In presence of the complex (10 μM) a bright red fluorescence image of MCF-7 cell lines is observed under fluorescence microscope. Moreover, the complex acts as effective catalyst towards transfer hydrogenation of ketones.
Roy, Puspendu,Sarkar, Deblina,Ghosh, Paramita,Manna, Chandan Kumar,Murmu, Nabendu,Mondal, Tapan Kumar
(2019/12/11)

Method for catalytic oxidation of cycloalkane by confinement porphyrin Co (II)
The invention relates to a method for catalytic oxidation of cycloalkane by confinement porphyrin Co (II). The method comprises the following steps: dispersing confinement cobalt porphyrin (II) in cycloalkane, sealing the reaction system, heating to 100-130 DEG C while stirring, introducing oxygen to 0.2-3.0 MPa, keeping the set temperature and oxygen pressure, stirring to react for 3.0-24.0 h, and carrying out post-treatment on a reaction solution to obtain products naphthenic alcohol and naphthenic ketone. The method achieves high selectivity of naphthenic alcohol and naphthenic ketone, andeffectively inhibits the generation of aliphatic diacid. The aliphatic diacid is low in selectivity, so that the continuity of the cycloalkane oxidation process and the separation of the products arefacilitated; the method has the potential of solving the problem that naphthenic alcohol and naphthenic ketone are easily and deeply oxidized to generate aliphatic diacid in the industrial cycloalkanecatalytic oxidation process; and the method is a novel efficient and feasible method for selective catalytic oxidation of cycloalkane.
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Paragraph 0071; 0072

(2020/05/01)

Confinement porphyrin Co (II), and preparation method and application thereof
Confinement porphyrin Co (II). A preparation method includes: under acidic condition, performing condensation on aromatic aldehyde and pyrrole in equal molar ratio to obtain a phenylporphyrin compound, and carrying out metallization in a chloroform-methanol solution to obtain porphyrin Cu (II), performing bromination and demetalization by perchloric acid to obtain confinement porphyrin, performingstirring reflux on the confinement porphyrin in a methanol solution for 12.0-24.0 h to obtain confinement porphyrin Co (II). An application includes: dissolving the confinement porphyrin Co (II) in naphthenic hydrocarbon and sealing the reaction system, stirring and heating the reaction system to 100-130 DEG C and feeding oxygen to 0.2-3.0 MPa; maintaining the set temperature and oxygen pressureand performing a stirring reaction for 3.0-24.0 h; performing after treatment on the reaction liquid to prepare the product. In the invention, generation of fatty diacid is effectively inhibited, andcontinuity of a naphthenic hydrocarbon oxidization process and product separation is facilitated. The invention has the potential of solving the problem that naphthene alcohols and naphthene ketones are liable to undergo deep oxidization and form the fatty diacid in an industrial naphthenic hydrocarbon catalytic oxidation process.
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Paragraph 0103-0104

(2020/04/17)

Method for synergistically catalyzing and oxidizing cycloparaffin through confined metalloporphyrin cobalt (II)/Cu (II) salt
The invention discloses a method for synergistically catalyzing and oxidizing cycloparaffin through confined metalloporphyrin cobalt (II)/Cu (II) salt. The preparation method comprises the following steps: dispersing confined metalloporphyrin cobalt (II) (0.001%-5%, g/mol) and Cu (II) salt (0.01%-10%, mol/mol) into cycloparaffin; and sealing the reaction system, heating the temperature to 90-150 DEG C while stirring, introducing an oxidant, keeping the set temperature and pressure, carrying out stirring and reacting for 2.0-24.0 hours, and carrying out after-treatment on the reaction solutionto obtain the products cycloalkyl alcohol and cycloalkyl ketone. The method disclosed by the invention has the advantages of high cycloalkyl alcohol and cycloalkyl ketone selectivity, low reaction temperature, few byproducts, small environmental influence and the like. In addition, the content of cycloalkyl hydroperoxide is low, and the safety coefficient is high. The invention provides an efficient, feasible and safe method for synthesizing cycloalkyl alcohol and cycloalkyl ketone through selective catalytic oxidation of cycloparaffin.
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Paragraph 0045-0046

(2020/12/10)

Complementary and selective oxidation of hydrocarbon derivatives by two cytochrome P450 enzymes of the same family
The cytochrome P450 enzymes CYP101B1 and CYP101C1, which are from the bacterium Novosphingobium aromaticivorans DSM12444, can hydroxylate norisoprenoids with high activity and selectivity. With the goal of expanding and establishing their substrate range with a view to developing applications, the oxidation of a selection of cyclic alkanes, ketones and alcohols was investigated. Cycloalkanes were oxidised, but both enzymes displayed moderate binding affinity and low levels of productive activity. We improved the binding and activity of these substrates with CYP101B1 by making the active site more hydrophobic by switching a histidine residue to a phenylalanine (H85F). The presence of a ketone moiety in the cycloalkane skeleton significantly improved the oxidation activity with both enzymes. CYP101C1 preferably catalysed the oxidation of cycloalkanones at the C-2 position whereas CYP101B1 oxidised these substrates with higher productivity and at positions remote from the carbonyl group. This demonstrates that the binding orientation of the cyclic ketones in the active site of each enzyme must be different. Linear ketones were also oxidised by both enzymes but with lower activity and selectivity. Cyclic substrates with an ester directing group were more efficiently oxidised by CYP101B1 than CYP101C1. Both enzymes catalysed oxidation of these esters with high regioselectively on the ring system remote from the ester directing group. CYP101C1 selectively oxidised certain terpenoid ester substrates, such as α-terpinyl and citronellyl acetate more effectively than CYP101B1. Overall, we establish that the high selectivity and activity of these enzymes could provide new biocatalytic routes to important fine chemicals.
Sarkar, Md. Raihan,Bell, Stephen G.
p. 5983 - 5995
(2020/10/08)

Reductive C-O, C-N, and C-S Cleavage by a Zirconium Catalyzed Hydrometalation/β-Elimination Approach
A zirconium catalyzed reductive cleavage of Csp3 and Csp2 carbon-heteroatom bonds is reported that makes use of a tethered alkene functionality as a traceless directing group. The reaction is successfully demonstrated on C-O, C-N, and C-S bonds and proposed to proceed via a hydrozirconation/β-heteroatom elimination sequence of an in situ formed zirconium hydride catalyst. The positional isomerization of the catalyst further enables the cleavage of homoallylic ethers and the removal of terminal allyl and propargyl groups.
Matt, Christof,K?lblin, Frederic,Streuff, Jan
supporting information
p. 6983 - 6988
(2019/09/09)

Synthesis, structural characterization and C–H activation property of a tetra-iron(III) cluster
A non-heme tetra-iron cluster, [Fe4 III(μ-O)2(μ-OAc)6(2,2′-bpy)2(H2O)2](NO3 ?)(OH?) (1), [OAc = acetate; 2,2′-bpy = 2,2′-bipyridine] containing oxido- and acetato-bridges was synthesized and structurally characterized by different spectroscopic methods including single crystal X-ray diffraction studies. X-ray crystal structure analysis of 1 revealed that tetra-iron complex was crystallized in monoclinic system with C2/c space group. Each of the Fe centres in 1 was found to exist in octahedral geometry and interconnected by oxido- and acetato-bridges. Bond valence sum (BVS) calculation recommended the existence of iron centres in +3 oxidation state. Variable temperature magnetic measurement authenticated the dominating antiferromagnetic ordering among the iron centres in the solid state of 1. This tetra-iron cluster was also evaluated as an efficient catalytic system towards the oxidation of both linear & cyclic alkanes without production of primary C–H bond oxidation products. Oxidation of secondary C–H bonds attested the formation of both the corresponding alcohols & ketones in 27–900 TONs. The tetra-iron catalytic system with Alcohol/Ketone values 0.2–1.7 indicated the involvement of freely diffusing carbon-centered radicals rather than metal based oxidant.
Dey, Dhananjay,Patra, Moumita,Al-Hunaiti, Afnan,Yadav, Hare Ram,Al-mherat, Afrah,Arar, Sharif,Maji, Milan,Choudhury, Angshuman Roy,Biswas, Bhaskar
p. 220 - 226
(2019/01/05)

Three Generations of Cobalt Porphyrins as Catalysts in the Oxidation of Cycloalkanes
Three generations of cobalt porphyrins were synthesized, physicochemically characterized by FTIR and UV/Vis spectroscopy as well as cyclic voltammetry and applied as catalysts in the oxidation of cycloalkanes with atmospheric molecular oxygen under mild c
Pamin, Katarzyna,Tabor, Edyta,Górecka, Sylwia,Kubiak, W?adys?aw W.,Rutkowska-Zbik, Dorota,Po?towicz, Jan
p. 684 - 691
(2018/12/13)

A Practical and Stereoselective In Situ NHC-Cobalt Catalytic System for Hydrogenation of Ketones and Aldehydes
Homogeneous catalytic hydrogenation of carbonyl groups is a synthetically useful and widely applied organic transformation. Sustainable chemistry goals require replacing conventional noble transition metal catalysts for hydrogenation by earth-abundant base metals. Herein, we report how a practical in situ catalytic system generated by easily available pincer NHC precursors, CoCl2, and a base enabled efficient and high-yielding hydrogenation of a broad range of ketones and aldehydes (over 50 examples and a maximum turnover number [TON] of 2,610). This is the first example of NHC-Co-catalyzed hydrogenation of C=O bonds using flexible pincer NHC ligands consisting of a N-H substructure. Diastereodivergent hydrogenation of substituted cyclohexanone derivatives was also realized by fine-tuning of the steric bulk of pincer NHC ligands. Additionally, a bis(NHCs)-Co complex was successfully isolated and fully characterized, and it exhibits excellent catalytic activity that equals that of the in-situ-formed catalytic system. Catalytic hydrogenation is a powerful tool for the reduction of organic compounds in both fine and bulk chemical industries. To improve sustainability, more ecofriendly, inexpensive, and earth-abundant base metals should be employed to replace the precious metals that currently dominate the development of hydrogenation catalysts. However, the majority of the base-metal catalysts that have been reported involve expensive, complex, and often air- and moisture-sensitive phosphine ligands, impeding their widespread application. From a mixture of the stable CoCl2, imidazole salts, and a base, our newly developed catalytic system that formed easily in situ enables efficient and stereoselective hydrogenation of C=O bonds. We anticipate that this easily accessible catalytic system will create opportunities for the design of practical base-metal hydrogenation catalysts. A practical in situ catalytic system generated by a mixture of easily available pincer NHC precursors, CoCl2, and a base enabled highly efficient hydrogenation of a broad range of ketones and aldehydes (over 50 examples and up to a turnover number [TON] of 2,610). Diastereodivergent hydrogenation of substituted cyclohexanone derivatives was also realized in high selectivities. Moreover, the preparation of a well-defined bis(NHCs)-Co complex via this pincer NHC ligand consisting of a N-H substructure was successful, and it exhibits equally excellent catalytic activity for the hydrogenation of C=O bonds.
Zhong, Rui,Wei, Zeyuan,Zhang, Wei,Liu, Shun,Liu, Qiang
supporting information
p. 1552 - 1566
(2019/06/14)

Method for preparing lactone compound by cycloalkane compound through oxidation
The invention discloses a method for preparing a lactone compound by a cycloalkane compound through oxidation. The method comprises the following steps of using the cycloalkane compound as the raw material, and further oxidizing by a catalysis system under the oxygen-containing atmosphere, so as to obtain the lactone compound, wherein the catalysis system comprises a catalyst and an additive; thecatalyst is selected from a cyclic organic nitrogen and oxygen free radical precursor in formulas (I), (II), (III) and (IV); in the formula, R1, R2 and R3 are independently selected from hydrogen atom, alkyl, cycloalkyl, aryl, heterocycle, hydroxyl, nitryl, or halogen, or at least two of R1, R2 and R3 form loops; the additive is selected from an aldehyde compound. The preparation method has the advantages that the corresponding lactone is prepared by the cycloalkane compound through a one-step method; the conditions are mild, the safety is high, and the metal catalytic oxidization is avoided;the selectivity of the target product, namely the lactone compound, is high. The formulae are shown in the description.
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Paragraph 0064; 0065; 0116-0119

(2019/02/04)

Method for preparing naphthenic alcohol and naphthenone by using molecular oxygen to selectively oxidize naphthenic hydrocarbon under synergistic catalysis of cobalt (II) salt/copper (II) salt
The invention provides a method for preparing naphthenic alcohol and naphthenone by using molecular oxygen to selectively oxidize naphthenic hydrocarbon under synergistic catalysis of a cobalt (II) salt/copper (II) salt. The method comprises the following steps: in an agate ball-milling tank, ball-milling a main catalyst cobalt (II) salt and a cocatalyst copper (II) salt at room temperature according to a molar ratio to obtain a cobalt (II) salt/copper (II) salt composite catalyst; in a stainless steel high-pressure reaction kettle with a polytetrafluoroethylene liner, dispersing the cobalt (II) salt/copper (II) salt composite catalyst into the naphthenic hydrocarbon, sealing the reaction kettle, conducting stirring and heating, and introducing an oxidizing agent oxygen; maintaining a settemperature and oxygen pressure to perform stirring reaction; and after the reaction, adding triphenylphosphine into a reaction mixture, and conducting stirring to reduce a generated peroxide at roomtemperature, so as to obtain the naphthenic alcohol and the naphthenone. The catalyst is cheap and easily available and the synthesis cost is low; the selectivity is high and generation of aliphatic diacid is effectively inhibited; and the aliphatic diacid selectivity is low, and continuity of the naphthenic hydrocarbon oxidization process and separation of products are facilitated.
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Paragraph 0108-0109

(2020/01/03)

Method for synergistically catalyzing and oxidizing cycloalkane by porphyrin cobalt (II)/zinc (II) salt
The invention discloses a method for synergistically catalyzing and oxidizing cycloalkane by porphyrin cobalt (II)/zinc (II) salt. The method comprises the following steps: dispersing porphyrin cobalt(II) and a zinc (II) salt in cycloalkane, sealing the reaction system, carrying out heating to 100-130 DEG C while stirring, introducing oxygen to 0.2-3 MPa, keeping a set temperature and oxygen pressure, carrying out stirring for reacting for 3-24 hours, and then carrying out after-treatment on the reaction solution to obtain product naphthenic alcohol and naphthenic ketone. According to the method disclosed by the invention, the naphthenic alcohol and the naphthenic ketone are high in selectivity, and generation of aliphatic diacid is effectively inhibited; a cocatalyst is cheap and is easily available, and synthesis cost of the naphthenic alcohol and naphthenic ketone is low; the aliphatic diacid is low in selectivity, so that continuity of a cycloalkane oxidation process and separation of products are facilitated; and the method has a potential of solving the problem that naphthenic alcohol and naphthenic ketone are easily and deeply oxidized to generate aliphatic diacid in industrial cycloalkane catalytic oxidation processes. The method is a novel efficient feasible method for selective catalytic oxidation of cycloalkane.
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Paragraph 0087; 0088

(2019/12/25)

A mild reaction conditions of the catalytic oxidation of cyclooctane new method (by machine translation)
A cyclooctane catalytic oxidation method, said method comprising: the metal porphyrin, cyclooctane mixing, at a temperature of 80 - 120 °C, O2 The pressure 0.6 - 2 mpa reaction under the condition of 2 - 48 H-, after processing reaction liquid, separating the oxidation product [...], cyclooctanol, ring octanone; the invention relates to a new method of cyclooctane catalytic oxidation reaction temperature is low, the catalyst amount is less, but in order to O2 As the oxidizing agent, environmental protection, cyclooctane can be the highly selective oxide cyclooctanol, ring octanone and [...], the catalytic oxidation of cyclooctane new method also has the simple operation, does not use an organic solvent, ring octanone selectivity and the like. (by machine translation)
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Paragraph 0017-0018; 0021-0022; 0031-0032

(2019/03/28)

Selective biocatalytic hydroxylation of unactivated methylene C-H bonds in cyclic alkyl substrates
The cytochrome P450 monooxygenase CYP101B1 from Novosphingobium aromaticivorans selectively hydroxylated methylene C-H bonds in cycloalkyl rings. Cycloketones and cycloalkyl esters containing C6, C8, C10 and C12 rings were oxidised with high selectively on the opposite side of the ring to the carbonyl substituent. Cyclodecanone was oxidised to oxabicycloundecanol derivatives in equilibrium with the hydroxycyclodecanones.
Sarkar, Md Raihan,Dasgupta, Samrat,Pyke, Simon M.,Bell, Stephen G.
supporting information
p. 5029 - 5032
(2019/05/21)

A Cu-Doped ZIF-8 metal organic framework as a heterogeneous solid catalyst for aerobic oxidation of benzylic hydrocarbons
Mixed-metal metal organic frameworks have received considerable attention in recent years and it has been shown that the activity of the parent metal organic framework (MOF) is often enhanced upon doping with external metal ions within the framework. In this context, Cu2+ ions with different loadings were incorporated within the ZIF-8 framework to obtain a series of Cu-doped ZIF-8 materials and their activity was examined in the aerobic oxidation of hydrocarbons. The as-synthesized Cu-doped solids were characterized by powder X-ray diffraction (XRD), ultraviolet diffuse reflectance spectroscopy (UV-DRS), scanning electron microscopy (SEM), Fourier Transform infrared (FT-IR), electron paramagnetic resonance (EPR) and inductively coupled plasma (ICP) analysis. The experimental results revealed that the activity of Cu-doped ZIF-8 is much higher than that of the parent ZIF-8 in all the tested substrates at 120 °C. Furthermore, the activity of the Cu-doped ZIF-8 with the highest Cu loading was eight fold higher than that of the parent ZIF-8 in the aerobic oxidation of cyclooctane (1) at 120 °C with more than 80% selectivity to the corresponding cyclooctanol/cyclooctanone (ol/one) mixture. Cu-doped ZIF-8 was reused two times with no significant drop in its activity under identical conditions. Furthermore, comparison of the two times reused solid with that of the fresh solid by powder XRD and SEM analysis revealed identical structural integrity and morphology, respectively during the oxidation reactions.
Nagarjun, Nagarathinam,Dhakshinamoorthy, Amarajothi
supporting information
p. 18702 - 18712
(2019/12/09)

Synthesis, crystal structure and immobilization of a new cobalt(ii) complex with a 2,4,6-tris(2-pyridyl)-1,3,5-triazine ligand on modified magnetic nanoparticles as a catalyst for the oxidation of alkanes
A new Co(ii) complex with formula [Co(tptz)Cl2]·2H2O (tptz = 2,4,6-tris(2-pyridyl)-1,3,5-triazine) has been synthesized and characterized by X-ray crystallography, elemental analyses and spectroscopic methods. It was then supported on modified Fe3O4 nanoparticles using tetraethylorthosilicate (TEOS) and (3-aminopropyl)trimethoxysilane (APTMS) and designated as a Fe3O4@SiO2@APTMS@complex nanocatalyst. The prepared nanocatalyst was characterized by means of FT-IR, Raman, XPS, EDX, XRD, VSM, SEM and TEM studies. The catalytic activity of the [Co(tptz)Cl2]·2H2O complex and Fe3O4@SiO2@APTMS@complex designated as catalysts A and B was used for oxidation of activated secondary alkanes such as fluorene, diphenyl methane, ethylbenzene, cyclooctane and adamantane. Observation of 39-99% conversions and 27-100% selectivities toward the corresponding ketones as well as the heterogeneity and reusability of the catalyst B seem promising.
Azarkamanzad, Zahra,Farzaneh, Faezeh,Maghami, Mahboobeh,Simpson, Jim
p. 12020 - 12031
(2019/08/07)

Oxygenation of styrenes catalyzed by N-doped carbon incarcerated cobalt nanoparticles
NCI-Co catalyzed olefin oxygenation reactions were investigated. Among the metals examined, including noble metals, the reaction proceeded specifically on Co catalysts, and nitrogen dopant was crucial for the catalytic activity. The presence of NaBH4 as a hydride source, the corresponding alcohols were obtained in high yields. The substrates bearing a reductant-sensitive functional group were made tolerant by changing the reductant and using an additive, and furthermore, the corresponding ketones were accessed by changing reaction conditions. A preliminary examination of other SOMOphiles suggested that the heterogeneous catalyst systems have the potential to be applied to more general hydrofunctionalization of olefins to form various kinds of bonds. Several mechanistic studies suggested that the reaction proceeded in a heterogeneous manner and formed a radical intermediate on cobalt nanoparticle species.
Yasukawa, Tomohiro,Kobayashi, Shū
supporting information
p. 1980 - 1985
(2019/12/24)

Mild C-H functionalization of alkanes catalyzed by bioinspired copper(ii) cores
Three new copper(ii) coordination compounds formulated as [Cu(H1.5bdea)2](hba)·2H2O (1), [Cu2(μ-Hbdea)2(aca)2]·4H2O (2), and [Cu2(μ-Hbdea)2(μ-bdca)]n (3) were generated by aqueous medium self-assembly synthesis from Cu(NO3)2, N-butyldiethanolamine (H2bdea) as a main N,O-chelating building block and different carboxylic acids [4-hydroxybenzoic (Hhba), 9-anthracenecarboxylic (Haca), or 4,4′-biphenyldicarboxylic (H2bdca) acid] as supporting carboxylate ligands. The structures of products range from discrete mono- (1) or dicopper(ii) (2) cores to a 1D coordination polymer (3), and widen a family of copper(ii) coordination compounds derived from H2bdea. The obtained compounds were applied as bioinspired homogeneous catalysts for the mild C-H functionalization of saturated hydrocarbons (cyclic and linear C5-C8 alkanes). Two model catalytic reactions were explored, namely the oxidation of hydrocarbons with H2O2 to a mixture of alcohols and ketones, and the carboxylation of alkanes with CO/S2O82- to carboxylic acids. Both processes proceed under mild conditions with a high efficiency and the effects of different parameters (e.g., reaction time and presence of acid promoter, amount of catalyst and solvent composition, substrate scope and selectivity features) were studied and discussed in detail. In particular, an interesting promoting effect of water was unveiled in the oxidation of cyclohexane that is especially remarkable in the reaction catalyzed by 3, thus allowing a potential use of diluted, in situ generated solutions of hydrogen peroxide. Moreover, the obtained values of product yields (up to 41% based on alkane substrate) are very high when dealing with the C-H functionalization of saturated hydrocarbons and the mild conditions of these catalytic reactions (50-60 °C, H2O/CH3CN medium). This study thus contributes to an important field of alkane functionalization and provides a notable example of new Cu-based catalytic systems that can be easily generated by self-assembly from simple and low-cost chemicals.
Kirillova, Marina V.,Fernandes, Tiago A.,André, Vania,Kirillov, Alexander M.
supporting information
p. 7706 - 7714
(2019/08/30)

Method for (II) preparing/cycloalkanol and cycloalkanone by synergetic (II) catalysis of molecular oxygen-selective oxidation of cycloalkane by using cobalt salt, namely, zinc salt of zinc salt (by machine translation)
In a stainless steel (II) high /(II) pressure reaction kettle with a polytetrafluoroethylene inner container, the cobalt salt is stirred and heated at room temperature to give an oxidant oxygen (II); a set temperature (II) and an oxygen pressure stirring reaction are kept; and the reaction (II) mixture/is (II) stirred and reduced to generate a peroxide, namely cycloalkanol and cycloalkanone (II)/(II). The catalyst has the advantages of cheap and easily available catalyst, low synthesis cost, high selectivity, effective inhibition of generation of aliphatic diacid, low selectivity of aliphatic diacid, and facilitation of serialization of the naphthenic acid process and separation of products. (by machine translation)
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Paragraph 0105-0106

(2019/12/08)

Liquid-phase oxidation of alkanes with molecular oxygen catalyzed by high valent iron-based perovskite
Hexagonal BaFeO3-δ containing high valent iron species acted as an efficient heterogeneous catalyst for the aerobic oxidation of alkanes without the need for additives. The activity of BaFeO3-δ was much higher than that of typical Fe3+/Fe2+-containing iron oxide-based catalysts, and the recovered catalyst could be reused without significant loss of catalytic performance.
Shibata, Satomi,Sugahara, Kosei,Kamata, Keigo,Hara, Michikazu
supporting information
p. 6772 - 6775
(2018/06/26)

Synthesis of α-Cyclooctyl- and α-Cyclopentadecylglycosides of N-Acetylmuramyl-L-Alanyl-D-Isoglutamine
N-Acetylmuramyl-L-alanyl-D-isoglutamine α-cyclooctyl- and α-cyclopentadecylglycosides were synthesized. The starting peracetylated α-N-glucosaminides were synthesized by reacting the cycloalkanols with peracetyl α-D-glucosaminyl chloride in the presence of Hg(II) iodide in CH3NO2 with heating or by using ZnCl2/tetrabutylammonium bromide in CH2Cl2 at room temperature. Sequential deacetylation, isopropyl protection, and alkylation by (S)-2-bromopropanoic acid gave α-cycloalkyl-4,6-O-isopropylidene-N-acetyl-D-muramic acids, condensation of which with the benzyl ester of L-Ala-D-iGln using the HOSu/DCC method and deprotection afforded the target glycopeptides.
Zemlyakov,Tsikalov,Tsikalova
p. 1139 - 1142
(2018/11/21)

Highly Selective Transfer Hydrogenation of Carbonyl Compounds Using La2O3
In the present study, we used rare earth oxides for the catalytic transfer hydrogenation of carbonyl compounds. Pretreated La2O3 showed better catalytic performance than various rare earth oxides for the reduction of carbonyl compounds. Reaction conditions, precursors, and donor hydrogen sources were also investigated to optimize the hydrogen transfer to furfural in 2-propanol. La2O3 provided a conversion of different carbonyl compounds and selectivity to the corresponding alcohols up to 100% and 99%, respectively. We also investigated a plausible mechanism using in situ IR and found that furfural was adsorbed on the catalyst surface in a different adsorption mode. Meanwhile, La(OH)3, a hydroxide derivative of La2O3 formed during the reaction, was also catalytically active.
Natsir, Taufik Abdillah,Hara, Takayoshi,Ichikuni, Nobuyuki,Shimazu, Shogo
p. 1561 - 1569
(2018/11/24)

An original one-pot approach to boronic esters using the titanium-catalyzed reaction of cyclic olefins with alkyldichloroboranes
Boronic esters (dicycloheptylalkylboronates, dicyclooctylalkylboronates, dicyclododecylalkylboronates, dibicyclo[2.2.1]hept-2-ylalkylboronates) are produced with yields ranging from moderate to excellent (52–96%) by the reaction between cyclic olefins (cycloheptene, cis-cyclooctene, cis/trans-cyclododecene, norbornene) and alkyldichloroboranes (alkyl = Et, n-Pent) in the presence of metallic magnesium and the Cp2TiCl2 catalyst with subsequent addition of water.
Khusainova, Liliya I.,Khafizova, Leila O.,Tyumkina, Tatyana V.,Ryazanov, Kirill S.,Popodko, Natalya R.,Dzhemilev, Usein M.
p. 8 - 11
(2018/07/29)

Three-Component Copper-Phosphonate-Auxiliary Ligand Systems: Proton Conductors and Efficient Catalysts in Mild Oxidative Functionalization of Cycloalkanes
The synthesis, structural characterization, topological analysis, proton conductivity, and catalytic properties are reported of two Cu(II)-based compounds, namely a dinuclear Cu(II) complex [Cu2(μ-VPA)2(phen)2(H2O)2]·8H2O (1) (H2VPA = vinylphosphonic acid, phen = 1,10-phenanthroline) and a 1D coordination polymer [Cu(μ-SO4)(phen)(H2O)2]∞ (2). Their structural features and H-bonding interactions were investigated in detail, showing that the metal-organic structures of 1 and 2 are extended by multiple hydrogen bonds to more complex 2D or 1D H-bonded architectures with the kgd [Shubnikov plane net (3.6.3.6)/dual] and SP 1-periodic net (4,4)(0,2) topology, respectively. These nets are primarily driven by the H-bonding interactions involving water ligands and H2O molecules of crystallization; besides, the (H2O)4/(H2O)5 clusters were identified in 1. Both 1 and 2 are moderate proton conductors, with proton conductivity values, σ = 3.65 × 10-6 and 3.94 × 10-6 S·cm-1, respectively (measured at 80 °C and 95% relative humidity). Compounds 1 and 2 are also efficient homogeneous catalysts for the mild oxidative functionalization of C5-C8 cycloalkanes (cyclopentane, cyclohexane, cycloheptane, and cyclooctane), namely for the oxidation by H2O2 to give cyclic alcohols and ketones and the hydrocarboxylation by CO/H2O and S2O82- to the corresponding cycloalkanecarboxylic acids as major products. The catalytic reactions proceed under mild conditions (50-60 °C) in aqueous acetonitrile medium, resulting in up to 34% product yields based on cycloalkane substrate.
Armakola, Eirini,Colodrero, Rosario M. P.,Bazaga-García, Montse,Salcedo, Inés R.,Choquesillo-Lazarte, Duane,Cabeza, Aurelio,Kirillova, Marina V.,Kirillov, Alexander M.,Demadis, Konstantinos D.
p. 10656 - 10666
(2018/09/13)

New boron reagents for cycloboration of α-olefins into boriranes under Cp2TiCl2 catalysis
The one-pot cycloboration of α-olefins (oct-1-ene, dec-1-ene) for a facile access to substituted boriranes has been carried out with the use of alkyl, arylalkyl, and cycloalkyl boron dichlorides (EtBCl2, n-PentBCl2, n-HexBCl2, Ph(CH2)2BCl2, cyclo-OctBCl2, 2-norbornylBCl2) under Cp2TiCl2 catalysis.
Khusainova, Liliya I.,Khafizova, Leila O.,Tyumkina, Tatyana V.,Ryazanov, Kirill S.,Popodko, Natalya R.,Dzhemilev, Usein M.
p. 73 - 77
(2018/08/23)

Interplay between H-bonding and interpenetration in an aqueous copper(ii)-aminoalcohol-pyromellitic acid system: self-assembly synthesis, structural features and catalysis
Two new copper(ii) coordination compounds, [Cu(H1.5mdea)2]2(H2pma) (1a) and [{Cu2(μ-Hmdea)2}2(μ4-pma)]n·2nH2O (1b), were self-assembled at different temperatures from the same multicomponent reaction system, comprising copper(ii) nitrate, N-methyldiethanolamine (H2mdea), pyromellitic acid (H4pma), and potassium hydroxide. Products 1a and 1b were isolated as microcrystalline solids and fully characterized and their structures were established by single-crystal X-ray diffraction. Compound 1a features the bis-aminoalcohol(ate) monocopper(ii) units and H2pma2? anions that are multiply interconnected by strong H-bonds into a firm 2D H-bonded layer. Compound 1b reveals the bis-aminoalcoholate dicopper(ii) motifs that are interlinked by the μ4-pma4? spacers into a 3D + 3D interpenetrated metal-organic framework. From a topological perspective, both networks of 1a and 1b are uninodal and driven by similar 4-connected H2pma2? or pma4? nodes, but result in distinct sql and dia topologies, respectively. Compound 1a was applied as an efficient catalyst for two model cycloalkane functionalization reactions: (1) oxidation by H2O2 to form cyclic alcohols and ketones and (2) hydrocarboxylation by CO/H2O and S2O82? to form cycloalkanecarboxylic acids. The substrate scope, effects of various reaction parameters, selectivity and mechanistic features were also investigated.
Fernandes, Tiago A.,Kirillova, Marina V.,André, Vania,Kirillov, Alexander M.
supporting information
p. 16674 - 16683
(2018/12/05)

Highly efficient and green oxidation of alkanes and alkylaromatics with hydrogen peroxide catalysed by silver and vanadyl on mesoporous silica-coated magnetite
A heterogeneous catalyst (FeSi/Ag/VO) based on silver and vanadyl as active sites and mesoporous silica-coated nanospheres of magnetite (Fe3O4@m-SiO2) as support was successfully prepared by deposition of Ag nanoparticles and the covalent grafting of vanadyl(IV) acetylacetonate on Fe3O4@m-SiO2. The catalyst exhibited excellent activity for the oxidation of alkanes, benzene and alkylaromatics using green oxidant H2O2 and oxalic acid in acetonitrile at 60?°C.
Nouri, Seyed Hadi,Hosseini-Monfared, Hassan
(2017/06/21)

Mesoporous Assembled Mn3O4 Nanoparticle Networks as Efficient Catalysts for Selective Oxidation of Alkenes and Aryl Alkanes
The design of nanoscale materials has been considered important for enhancing their surface properties for catalysis. Metal oxide nanoparticles have a large number of exposed surface active sites, but they suffer from low reactivity and poor stability resulting from excessive aggregation into less active microscopic structures. Herein, the synthesis of mesoporous Mn3O4 nanoparticle assemblies by polymer-assisted self-assembly is presented and their catalytic activity is demonstrated in the oxidation of various saturated and unsaturated hydrocarbons, including aromatic alkenes and aryl alkanes, in the presence of tert-butyl hydroperoxide as a mild oxidant. It is also shown through comparative studies that the high catalytic activity and stability of these Mn3O4 assemblies arise from the unique three-dimensional open-pore structure, high internal surface area (90 m2 g?1) and uniform mesopores (≈6.6 nm in size).
Skliri, Euaggelia,Papadogiorgakis, Stelios,Lykakis, Ioannis N.,Armatas, Gerasimos S.
p. 136 - 143
(2017/01/18)

Homoleptic iron(II) and cobalt(II) bis(phosphoranimide) complexes for the selective hydrofunctionalization of unsaturated molecules
Low-coordinate homoleptic bulky M2(NPtBu3)4 (M = Fe (A), Co (B)) complexes were synthesized and characterized as dimeric structures by crystallographic studies. The iron complex A can catalyze the hydroboration reaction of aldehydes and ketones. The cobalt complex B outperformed its iron counterpart in hydrogenations of several typical alkenes and alkynes under mild conditions. Poisoning experiments indicate that the Co(ii)/HBpin catalytic system could be homogeneous.
Bai, Tao,Janes, Trevor,Song, Datong
p. 12408 - 12412
(2017/10/06)

Synthesis of β-cycloalkylglycosides of Muramyl Dipeptide
β-Cyclooctyl-, β-cyclodecyl-, and β-cyclopentadecylglycosides of N-acetylmuramyl-L-alanyl-D-isoglutamine were prepared in yields of 39, 18, and 25%, respectively, (calculated for muramic acid) via the reaction of β-cycloalkyl-4,6-O-isopropylidene-N-acetyl-D-muramic acids with the benzyl ester of L-Ala-D-iGln using the HOSu/DCC method followed by deprotection.
Zemlyakov,Tsikalova,Tsikalov
p. 929 - 932
(2017/10/07)

Transfer hydrogenation of ketones catalysed by half-sandwich (η6-p-cymene) ruthenium(II) complexes incorporating benzoylhydrazone ligands
Neutral half-sandwich η6-p-cymene ruthenium(II) complexes of general formula [Ru(η6-p-cymene)Cl(L)] (HL?=?monobasic O, N bidendate benzoylhydrazone ligand) have been synthesized from the reaction of [Ru(η6-p-cymene)(μ-Cl)Cl]2 with acetophenone benzoylhydrazone ligands. All the complexes have been characterized using analytical and spectroscopic (Fourier transform infrared, UV–visible, 1H NMR, 13C NMR) techniques. The molecular structures of three of the complexes have been determined using single-crystal X-ray diffraction, indicating a pseudo-octahedral geometry around the ruthenium(II) ion. All the ruthenium(II) arene complexes were explored as catalysts for transfer hydrogenation of a wide range of aromatic, cyclic and aliphatic ketones with 2-propanol using 0.1?mol% catalyst loading, and conversions of up to 100% were obtained. Further, the influence of other variables on the transfer hydrogenation reaction, such as base, temperature, catalyst loading and substrate scope, was also investigated.
Mohan, Nanjan,Ramesh, Rengan
(2017/06/21)

Mild oxidative C?H functionalization of alkanes and alcohols using a magnetic core-shell Fe3O4@mSiO2@Cu4 nanocatalyst
A new hybrid Fe3O4@mSiO2@Cu4 material was constructed by loading a bio-inspired tetracopper(II) coordination compound [Cu4(μ4-O){N(CH2CH2O)3}4(BOH)4][BF4]2 (Cu4) onto the Fe3O4@mSiO2 core-shell nanoparticles (NPs) composed of a magnetite (Fe3O4) core and mesoporous silica (mSiO2) shell with perpendicularly aligned channels. The obtained Fe3O4@mSiO2@Cu4 magnetic nanoparticles were characterized by transmission electron microscopy (TEM), FT-IR spectroscopy, thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD), and field-dependent magnetization. This hybrid material acts as a magnetically recoverable C?H functionalization nanocatalyst, namely for the mild oxidation, by t-butyl hydroperoxide at 50–70?°C in acetonitrile medium, of cycloalkanes (cyclopentane, cyclohexane, cycloheptane, and cyclooctane) to the corresponding alcohols and ketones (with up to ～15% yields based on cycloalkane; TON 335). A related oxidation process using cyclohexanol as a more reactive substrate leads to the formation of cyclohexanone in up to ～25% yield (TON 570). The Fe3O4@mSiO2@Cu4 nanocatalyst can be recycled five times without an appreciable loss of activity. The bond-, regio-, and stereoselectivity parameters were investigated in the oxidation of different alkane substrates (n-hexane, n-heptane, n-octane, methylcyclohexane, adamantane, cis- and trans-1,2-demethylcyclohexane), and the obtained results were compared with the homogeneous systems based on the Cu4 catalyst. In particular, the high bond selectivity parameters detected in the oxidation of methylcyclohexane (1°:2°:3° of 1:8:142) and adamantane (2°:3° of 1:21) catalyzed by Fe3O4@mSiO2@Cu4 suggest that the reactions possibly occur in hydrophobic pockets of the nanocatalyst.
Kirillova, Marina V.,Santos, Carla I.M.,Wu, Wenyu,Tang, Yu,Kirillov, Alexander M.
p. 343 - 349
(2016/12/16)