- Nickel-Catalyzed NO Group Transfer Coupled with NOxConversion
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Nitrogen oxide (NOx) conversion is an important process for balancing the global nitrogen cycle. Distinct from the biological NOx transformation, we have devised a synthetic approach to this issue by utilizing a bifunctional metal catalyst for producing value-added products from NOx. Here, we present a novel catalysis based on a Ni pincer system, effectively converting Ni-NOx to Ni-NO via deoxygenation with CO(g). This is followed by transfer of the in situ generated nitroso group to organic substrates, which favorably occurs at the flattened Ni(I)-NO site via its nucleophilic reaction. Successful catalytic production of oximes from benzyl halides using NaNO2 is presented with a turnover number of >200 under mild conditions. In a key step of the catalysis, a nickel(I)-?NO species effectively activates alkyl halides, which is carefully evaluated by both experimental and theoretical methods. Our nickel catalyst effectively fulfills a dual purpose, namely, deoxygenating NOx anions and catalyzing C-N coupling.
- Padmanaban, Sudakar,Choi, Jonghoon,Vazquez-Lima, Hugo,Ko, Donghwi,Yoo, Dagyum,Gwak, Jinseong,Cho, Kyung-Bin,Lee, Yunho
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supporting information
p. 4585 - 4593
(2022/03/02)
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- Site-specific catalytic activities to facilitate solvent-free aerobic oxidation of cyclohexylamine to cyclohexanone oxime over highly efficient Nb-modified SBA-15 catalysts
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The development of highly active and selective heterogeneous catalysts for efficient oxidation of cyclohexylamine to cyclohexanone oxime is a challenge associated with the highly sensitive nitrogen center of cyclohexylamine. In this work, dispersed Nb oxide supported on SBA-15 catalysts are disclosed to efficiently catalyze the selective oxidation of cyclohexylamine with high conversion (>75%) and selectivity (>84%) to cyclohexanone oxime by O2without any addition of solvent (TOF = 469.8 h?1, based on the molar amount of Nb sites). The role of the active-site structure identity in dictating the site-specific catalytic activities is probed with the help of different reaction and control conditions and multiple spectroscopy methods. Complementary to the experimental results, further poisoning tests (with KSCN or dehydroxylation reagents) and DFT computational studies clearly unveil that the surface exposed active centers toward activation of the reactants are quite different: the surface -OH groups can catch the NH2group from cyclohexylamine by forming a hydrogen bond and lead to a more facile cyclohexylamine oxidation to desired products, while the monomeric or oligomeric Nb sites with a highly distorted structure play a key role in the dissociation of O2molecules beneficial for insertion of active oxygen species into cyclohexylamine. These catalysts exhibit not only satisfactory recyclability for cyclohexylamine oxidation but also efficiently catalyze the aerobic oxidation of a wide range of amines under solvent-free conditions.
- Ding, Wei,Mao, Liqiu,Peng, Haoyu,Yin, Dulin,Zhong, Wenzhou
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p. 3409 - 3422
(2020/06/09)
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- Facile access to nitroalkanes: Nitration of alkanes by selective C[sbnd]H nitration using metal nitrate, catalyzed by in-situ generated metal oxide
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Direct C ? H functionalization of inactive alkanes is an important strategy to streamline the preparation of functional molecules. Herein, we describe an operationally simple and effective alkane C ? H nitration reaction to access versatile nitroalkanes without cleavage of the C ? C skeleton. Nontoxic and inexpensive metal nitrate (Fe(NO3)3·9H2O) plays a dual role as catalyst precursors as well as nitro sources for the transformation. Experimental evidence and theoretical modeling have shown the formation of iron oxide as a key catalytic species for the alkane C ? H and NO2 activation, which favors a stepwise radical mechanism with initial alkyl radical formation.
- Li, Na,Mao, Liqiu,Peng, Haoyu,Peng, Ling,Yin, Dulin,You, Kuiyi,Zhong, Wenzhou
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- Green synthesis method for preparing nitroalkanes by oxime oxidation
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The invention belongs to the field of organic chemical industries, and provides a green synthesis method for preparing nitroalkanes by oxime oxidation. At the temperature of 55 to 120 DEG C and under the pressure of 0 to 1.0 MPa, oxime, a solvent and hydrogen peroxide are reacted for 20 to 200min in the presence of certain amounts of nanoporous skeleton metal hybrid catalysts and cocatalysts, a reaction liquid is subjected to membrane separation, the catalysts can be repeatedly used for more than 7 times, and distilled to obtain nitroalkane products, the purity of the products is not less than 99%, and the yield of the products is not less than 95%. Furthermore, the green synthesis method for preparing nitroalkanes by the oxime oxidation disclosed by the invention is a green synthesis method of nitroalkanes, and suitable for large-scale industrialized production.
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Paragraph 0037; 0038
(2017/08/29)
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- Silver(I)-Promoted ipso-Nitration of Carboxylic Acids by Nitronium Tetrafluoroborate
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A novel and efficient method for the regioselective nitration of a series of aliphatic and aromatic carboxylic acids to their corresponding nitro compounds using nitronium tetrafluoroborate and silver carbonate in dimethylacetamide has been described. This transformation is believed to proceed via the alkyl-silver or aryl-silver intermediate, which subsequently reacts with the nitronium ion to form nitro substances. Mild reaction conditions, tolerant of a broad range of functional groups, and formation of only the ipso-nitrated products are the key features of this methodology when compared to known methods for syntheses of nitroalkyls and nitroarenes.
- Natarajan, Palani,Chaudhary, Renu,Venugopalan, Paloth
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p. 10498 - 10504
(2015/11/18)
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- NITRATED HYDROCARBONS, DERIVATIVES, AND PROCESSES FOR THEIR MANUFACTURE
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Provided is a process for the formation of nitrated compounds by the nitration of hydrocarbon compounds with dilute nitric acid. Also provided are processes for preparing industrially useful downstream derivatives of the nitrated compounds, as well as novel nitrated compounds and derivatives, and methods of using the derivatives in various applications.
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Page/Page column 30-31; 33
(2009/12/02)
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- Oxidation of azides by the HOF·CH3CN: A novel synthesis of nitro compounds
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The HOF·CH3CN complex, readily prepared by passing F 2 through aqueous acetonitrile, is an exceptionally efficient oxygen transfer agent. It is unique in its capacity to oxidize various azides into the corresponding nitro derivatives. This method requires short reactions times and room temperature or below, and the desired nitro compounds were usually isolated in very good yields. The respective nitroso derivatives are believed to be the intermediates in this reaction. Functional groups such as aromatic rings, ketones, nitriles, halides, alcohols, and esters are tolerated. Sulfides react with HOF·CH3CN usually at the same rate as azides. Amines and olefins, however, react faster, so they have to be protected first. Nitro derivatives with various oxygen isotopes can be made using the labeled H 18OF·CH3CN. In the case of chiral azides the stereochemistry around the nitrogen-bonded carbons is retained.
- Carmeli, Mira,Rozen, Shlomo
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p. 4585 - 4589
(2007/10/03)
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- Anti-Markovnikov Hydrofunctionalization of Olefins Mediated by Rhodium-Porphyrin Complexes
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A rationally designed mechanistic approach to anti-Markovnikov olefin hydrofunctionalization and its application to the synthesis of heterocycles are described. Porphyrin-rhodium complexes have been shown to exhibit remarkable reactivity and selectivity for each step of the proposed catalytic cycle (see scheme). A critical step of this reaction sequence is a new, facile, and remarkably general carbon-heteroatom bond-forming reductive elimination.
- Sanford, Melanie S.,Groves, John T.
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p. 588 - 590
(2007/10/03)
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- SRN1 reactions in the nitrobenzo[1,3]dioxole series
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5-Chloromethyl-6-nitrobenzo[1,3]dioxole has been shown to react with 2-nitropropane anion to give C-alkylation by an SRN1 mechanism. The reaction was extended to various aliphatic, cyclic, and heterocyclic nitronate anions, leading to a new series of nitrobenzo[1,3]dioxole derivatives.
- Meuche-Albeny,Rathelot,Crozet,Vanelle
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p. 989 - 997
(2007/10/03)
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- From azides to nitro compounds in a few seconds using HOF·CH3CN
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HOF·CH3CN, a very efficient oxygen-transfer agent, was reacted with various azides to form the corresponding nitro compounds in excellent yields and in very short reaction times. The respective nitroso derivatives were found to be intermediates in this reaction. When the azides were reacted with MCPBA or DMDO, no reaction took place, and the starting materials were fully recovered. Copyright
- Rozen, Shlomo,Carmeli, Mira
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p. 8118 - 8119
(2007/10/03)
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- An efficient nitration of light alkanes and the alkyl side-chain of aromatic compounds with nitrogen dioxide and nitric acid catalyzed by N-hydroxyphthalimide
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Nitration of light alkanes and the alkyl side-chain of aromatic compounds with NO2 and HNO3 was successfully achieved by the use of N-hydroxyphthalimide (NHPI) as a catalyst under relatively mild conditions. For example, the nitration of propane with NO2 catalyzed by NHPI at 100 °C for 14 h gave 2-nitropropane in good yield without formation of 1-nitropropane and cleaved products such as nitroethane and nitromethane. Various aliphatic nitroalkanes, which are difficult to prepare by conventional methods, could be selectively obtained by means of the present methodology by using NHPI as the key catalyst. In addition, the side-chain nitration of alkylbenzenes such as toluene was selectively carried out to lead to α-nitrotoluene without the ring nitration. The present reaction provides an efficient selective method for the nitration of light alkanes and alkylbenzenes, which has been very difficult to carry out so far.
- Nishiwaki, Yoshiki,Sakaguchi, Satoshi,Ishii, Yasutaka
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p. 5663 - 5668
(2007/10/03)
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- A versatile method for the conversion of oximes to nitroalkanes
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A convenient oxidation of oximes to nitroalkanes has been developed using oxone in acetonitrile.
- Bose, D. Subhas,Vanajatha
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p. 4531 - 4535
(2007/10/03)
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- Spectrochemical analysis of the laser-induced nitration of three cycloalkanes
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The tunable continuous wave carbon dioxide laser-induced reactions of cyclopropane, cyclobutane and cyclopentane with NO2 have been carried out under a variety of reaction conditions.Presented herein is our qualitative Fourier transform infrared spectroscopy and gas chromatography - mass spectroscopy spectrochemical analysis of the product mixtures.Optimal conditions were found for producing nitrocycloalkanes while reducing or eliminating the production of undesirable products.The array of products was found to be highly sensitive to the specific reaction conditions.
- Stanley, Ann E.,Godbey, Susan E.,Bonicamp, Judith M.,Ludwick, Larry M.
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p. 1987 - 1998
(2007/10/02)
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- Structure, Synthesis, and Properties of Some Persubstituted 1,2-Dinitroethanes. In Quest of Nitrocyclopropyl-Anion Derivatives
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Attempts to deprotonate nitrocyclopropane led to solutions which showed strong ESR. signals (Fig. 1) and from which 1-nitro-1'-nitroso-bicyclopropyl (3) and 1,1'-dinitro-bicyclopropyl (2) were isolated.The activation energy for rotation about the central C,C-bond of 2 is estimated to be about 12 kcal/mol (1H-NMR. spectra in Fig. 2).In contrast, the open-chain analoque 2,3-dimethyl-2,3-dinitrobutane (1) shows a metyl singlet down to -70 deg C.Low-temperature X-ray analyses of 1, 2, 3, and also of 1,1'-dinitro-bicyclobutyl (4) show that all four molecules have gauche-conformations but reveal striking structural differences between the open-chain and the cyclic derivatives (Fig. 4-6): the central C,C-bond is long in 1 (1.575 Angstroem), short in 2 (1.479 Angstroem); the C,N-bonds are long in 1 (1.549 Angstroem), short in 2 (1.488 Angstroem); the orientation of the nitro groups is bisected in 2 and perpendicular in 1.The crystal structure of the nitro-nitroso compound 3 is isimorphous with that of the dinitro compound 2 and thus disordered (Fig. 15-16).The effect of the nitro group as ?-electron acceptor on the molecular conformations and bond lengths is discussed.From analysis of the anisotropic vibrational parameters of 2 the root-mean-square librational amplitude of the nitro groups about their C,N-bonds is estimated to be about 5.8 deg at 95 K, corresponding to a rotational barrier of about 9 kcal/mol, i. e. the same order of magnitude as the NMR. estimate of about 12 kcal/mol for C,C-rotation.
- Kai, Yasushi,Knochel,Paul,Kwiatkowski, Stefan,Dunitz, Jack D.,Oth, Jean F. M.,et al.
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p. 137 - 161
(2007/10/02)
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- Photooxidation of C5-C7 Cycloalkanes in the NO-H2O-Air System
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Photooxidation of C5-C7 cycloalkane-NO-H2O-air systems was investigated.Reaction products were analyzed by FID gas chromatography (GC), GC/Ms, and FT IR.Cycloalkanone and cycloalkyl nitrate were observed to form as undergraded products.Among the C5-C7 cycloalkanes, the ratios of cycloalkyl nitrate produced to cycloalkane consumed were nearly equal (0.05-0.1), while marked variations were observed in the ratios of cycloalkanone produced to cycloalkane consumed (0.0016, 0.23, and 0.031 for C5, C6, and C7 cycloalkanes, respectively).These differences were explained by the ring rupture of cycloalkane ring, assuming that the extent of the ring rupture process depends on the strain energy of the cycloalkane ring.Cycloalkanone and cycloalkyl nitrate were minor product except for cyclohexanone, which amounted 20-30percent of cyclohexane consumed.Formaldehyde was observed as a ring rupture product (3-9percent of cycloalkane consumed).Major products were unidentified carbonyls produced by ring cleavage reactions.These carbonyls amounted to about 45percent of cycloalkane consumed.Formation of carbonyls and formaldehyde could be explained by the ring cleavage decomposition of the vibrationally hot cycloalkyloxy radicals.
- Takagi, H.,Washida, N.,Banbow, H.,Akimoto, H.,Okuda, M.
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p. 2701 - 2705
(2007/10/02)
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- AN EFFECTIVE AND MILD METHOD FOR THE CONVERSION OF OXIMES TO SECONDARY NITRO COMPOUNDS
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A mild and efficient process for the conversion of cyclic ketones to staurated nitro compounds, as outlined in eq. 1 below, is described.
- Corey, E. J.,Estreicher, Herbert
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p. 1117 - 1120
(2007/10/02)
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