- Reductive amination of aldehydes and ketones with sodium borohydride supported onto HZSM-5 zeolite under microwave irradiation in a solvent free system
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Sodium borohydride supported onto a HZSM-5 zeolite is presented as a general reducing agent for the reductive amination of aldehydes and ketones under microwave irradiation in solventless system. Copyright Taylor & Francis Inc.
- Oskooie, Hossein A.,Amiri, Somaih Solemani,Heravi, Majid M.,Ghassemzadeh, Mitra
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Read Online
- The azaallylic anion as a synthon for Pd-catalyzed synthesis of heterocycles: domino two- and three-component synthesis of indoles
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(Chemical Equation Presented) Piecing it all together with palladium: Two- and three-component cascade processes that are promoted by a multifunctional Pd catalyst lead to indoles in a highly efficient manner (see scheme). The key step is the Pd-catalyzed α-arylation of imines with o-dihalobenzene derivatives.
- Barluenga, Jose,Jimenez-Aquino, Agustin,Valdes, Carlos,Aznar, Fernando
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Read Online
- Three-Component Cascade Reactions with 2,3-Diketoesters: A Novel Metal-Free Synthesis of 5-Vinyl-pyrrole and 4-Hydroxy-indole Derivatives
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5-Vinyl-pyrrole and 4-hydroxy-indole derivatives are synthesized by metal-free aldol/cyclization/aromatization cascade reactions of in situ generated enamines with 2,3-diketoesters. This convenient atom-economical process produces multifunctional pyrrole and indole products in moderate to good yields.
- Sha, Qiang,Arman, Hadi,Doyle, Michael P.
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Read Online
- Sulfated polyborate: A dual catalyst for the reductive amination of aldehydes and ketones by NaBH4
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An efficient, quick, and environment-friendly one-pot reductive amination of aldehydes or ketones was developed. In ethanol at 70 °C, a imination catalyzed by sulfated polyborate and further reduced by sodium borohydride yields various amines. The present method has many significant benefits, including a shorter reaction time, excellent yields, and a hassle-free, straightforward experimental process. The reaction has a wide range of applications due to its flexibility, including secondary amine for reductive amination.
- Ganwir, Prerna,Chaturbhuj, Ganesh
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supporting information
(2021/05/19)
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- Direct Synthesis of Indoles from Azoarenes and Ketones with Bis(neopentylglycolato)diboron Using 4,4′-Bipyridyl as an Organocatalyst
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Multifunctionalized indole derivatives were prepared by reducing azoarenes in the presence of ketones and bis(neopentylglycolato)diboron (B2nep2) with a catalytic amount of 4,4′-bipyridyl under neutral reaction conditions, where 4,4′-bipyridyl acted as an organocatalyst to activate the B-B bond of B2nep2 and form N,N′-diboryl-1,2-diarylhydrazines as key intermediates. Further reaction of N,N′-diboryl-1,2-diarylhydrazines with ketones afforded N-vinyl-1,2-diarylhydrazines, which rearranged to the corresponding indoles via the Fischer indole mechanism. This organocatalytic system was applied to diverse alkyl cyclic ketones, dialkyl, and alkyl/aryl ketones, including heteroatoms. Methyl alkyl ketones gave the corresponding 2-methyl-3-substituted indoles in a regioselective manner. This protocol allowed us to expand the preparation of indoles having high compatibility with not only electron-donating and electron-withdrawing groups but also N- and O-protecting functional groups.
- Misal Castro, Luis C.,Sultan, Ibrahim,Nishi, Kohei,Tsurugi, Hayato,Mashima, Kazushi
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p. 3287 - 3299
(2021/03/01)
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- Reductive amination of ketones/aldehydes with amines using BH3N(C2H5)3as a reductant
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Herein, we report the first example of efficient reductive amination of ketones/aldehydes with amines using BH3N(C2H5)3 as a catalyst and a reductant under mild conditions, affording various tertiary and secondary amines in excellent yields. A mechanistic study indicates that BH3N(C2H5)3 plays a dual function role of promoting imine and iminium formation and serving as a reductant in reductive amination. This journal is
- Zou, Qizhuang,Liu, Fei,Zhao, Tianxiang,Hu, Xingbang
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supporting information
p. 8588 - 8591
(2021/09/04)
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- Cu/Ni-doped sulfated zirconium oxide immobilized on CdFe2O4 NPs: a cheap, sustainable and magnetically recyclable inorgano-catalyst for the efficient preparation of α-aminonitriles in aqueous media
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Abstract: A new multifunctional bimetallic nanocatalyst was prepared by immobilization of Cu/Ni-doped sulfated zirconium oxide on magnetic cadmium ferrite (CdFe2O4@SiO2@ZrO2/SO42?/Cu/Ni) and used as an efficient recyclable catalyst for one-pot as well as stepwise preparation of α-aminonitriles under mild conditions. The magnetic nanocatalyst was characterized by FTIR, TGA, VSM, XRD, EDX, FE-SEM, and TEM analyses. Also, the surface acidity of the catalyst was measured by pyridine adsorption assay. The catalyst possesses various active sites which could catalyst a variety of aromatic and aliphatic aldehydes to the corresponding α-amionitriles under moderate to high yields in the presence of aniline. Furthermore, transformation of ketones to the desired α-amionitriles and some bis-aminonitriles was also performed by this method. The catalyst could be readily recovered from the reaction mixture and reused for several times without significant loss of activity. Graphic abstract: A general and efficient method has been developed for transformation of a variety of aliphatic, aromatic aldehydes and ketones to the corresponding α-aminonitriles using a multifunctional recyclable CdFe2O4@SiO2@ZrO2/SO42?/Cu/Ni nanocatalyst.[Figure not available: see fulltext.]
- Nasseri, Mohammad Ali,Ramezani-Moghadam, Simin,Kazemnejadi, Milad,Allahresani, Ali
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p. 4233 - 4256
(2020/07/08)
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- Colloidal and Nanosized Catalysts in Organic Synthesis: XXIII. Reductive Amination of Carbonyl Compounds Catalyzed by Nickel Nanoparticles in a Plug-Flow Reactor
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Reductive amination of aldehydes and ketones with primary and secondary amines under catalysis with nickel nanoparticles supported on zeolite X, MgO, or activated carbon in the gas phase or in the gas-liquid system in a plug-flow reactor proceeds at atmospheric pressure of hydrogen with the formation of secondary or tertiary amines in high yield.
- Mokhov, V. M.,Nebykov, D. N.,Paputina, A. N.,Popov, Yu. V.,Shishkin, E. V.
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p. 2333 - 2340
(2020/02/25)
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- Metal-free nitrogen -doped carbon nanosheets: A catalyst for the direct synthesis of imines under mild conditions
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Herein, a highly stable, porous, multifunctional and metal-free catalyst was developed, which exhibited significant catalytic performance in the oxidation of amines and transfer hydrogenation of nitriles under mild conditions; this could be attributed to the presence of numerous active sites and their outstanding BET surface area. The obtained results showed that most of the yields of imines exceeded 90%, and the cycling performance of the catalyst could be at least seven runs without any decay in the reaction activity, which could be comparable to those of metal catalysts. Subsequently, a kinetic study has demonstrated that the apparent activation energy for the direct synthesis of imines from amines is 67.39 kJ mol-1, which has been performed to testify that the catalytic performances are rational. Via catalyst characterizations and experimental data, graphitic-N has been proven to be the active site of the catalyst. Hence, this study is beneficial to comprehend the mechanism of action of a metal-free N-doped carbon catalyst in the formation of imines.
- Wang, Kaizhi,Jiang, Pengbo,Yang, Ming,Ma, Ping,Qin, Jiaheng,Huang, Xiaokang,Ma, Lei,Li, Rong
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p. 2448 - 2461
(2019/05/17)
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- Oxidative Rearrangement of Primary Amines Using PhI(OAc)2 and Cs2CO3
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An oxidative rearrangement of primary amines mediated by a hypervalent iodine(III) reagent is herein reported. The combination of PhI(OAc)2 and Cs2CO3 proves highly efficient at inducing the direct 1,2-C to N migration of primary amines, which can be applied to the preparation of both acyclic and cyclic amines. A mechanistic study shows that the rearrangement proceeds via a concerted mechanism.
- Yamakoshi, Wataru,Arisawa, Mitsuhiro,Murai, Kenichi
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supporting information
(2019/05/08)
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- H2 Activation by Non-Transition-Metal Systems: Hydrogenation of Aldimines and Ketimines with LiN(SiMe3)2
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In recent years, H2 activation at non-transition-metal centers has met with increasing attention. Here, a system in which H2 is activated and transferred to aldimines and ketimines using substoichiometric amounts of lithium bis(trimethylsilyl)amide is reported. Notably, the reaction tolerates the presence of acidic protons in the α-position. Mechanistic investigations indicated that the reaction proceeds via a lithium hydride intermediate as the actual reductant.
- Elliott, Daniel C.,Marti, Alex,Mauleón, Pablo,Pfaltz, Andreas
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supporting information
p. 1918 - 1922
(2019/01/16)
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- Formic acid catalyzed one-pot synthesis of α-aminophosphonates: an efficient, inexpensive and environmental friendly organocatalyst
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Abstract: Aqueous formic acid is used for the synthesis of α-aminophosphonates through Kabachnik–Fields reaction applying aromatic amine, phosphite, and carbonyl compounds. Using formic acid as an efficient and low-cost organocatalyst provides environmental friendly, high yields, low reaction time and mild reaction condition. The isolated products were analyzed by IR, NMR, and mass techniques. Graphical abstract: [Figure not available: see fulltext.].
- Azarnia Mehraban, Jamshid,Jalali, Mahsa Sadat,Heydari, Akbar
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p. 2215 - 2223
(2018/08/04)
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- Transition-Metal-Free Addition of Acetylenes to Ketimines: the First Base-Catalyzed Ethynylation of the C=N Bond
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A one-pot transition metal-free synthesis of propargylamines in good to excellent yield from ketone-derived imines and aryl- and hetarylacetylenes in the presence of KOBut/DMSO superbase system (40 °C, 10 min) has been developed. The reaction i
- Bidusenko, Ivan A.,Schmidt, Elena Yu.,Ushakov, Igor A.,Trofimov, Boris A.
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supporting information
p. 4845 - 4849
(2018/09/14)
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- Versatile routes for synthesis of diarylamines through acceptorless dehydrogenative aromatization catalysis over supported gold-palladium bimetallic nanoparticles
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Diarylamines are an important class of widely utilized chemicals, and development of diverse procedures for their synthesis is of great importance. Herein, we have successfully developed novel versatile catalytic procedures for the synthesis of diarylamines through acceptorless dehydrogenative aromatization. In the presence of a gold-palladium alloy nanoparticle catalyst (Au-Pd/TiO2), various symmetrically substituted diarylamines could be synthesized starting from cyclohexylamines. The observed catalysis of Au-Pd/TiO2 was heterogeneous in nature and Au-Pd/TiO2 could be reused several times without severe loss of catalytic performance. This transformation needs no oxidants and generates molecular hydrogen (three equivalents with respect to cyclohexylamines) and ammonia as the side products. These features highlight the environmentally benign nature of the present transformation. Furthermore, in the presence of Au-Pd/TiO2, various kinds of structurally diverse unsymmetrically substituted diarylamines could successfully be synthesized starting from various combinations of substrates such as (i) anilines and cyclohexanones, (ii) cyclohexylamines and cyclohexanones, and (iii) nitrobenzenes and cyclohexanols. The role of the catalyst and the reaction pathways were investigated in detail for the transformation of cyclohexylamines. The catalytic performance was strongly influenced by the nature of the catalyst. In the presence of a supported gold nanoparticle catalyst (Au/TiO2), the desired diarylamines were hardly produced. Although a supported palladium nanoparticle catalyst (Pd/TiO2) gave the desired diarylamines, the catalytic activity was inferior to that of Au-Pd/TiO2. Moreover, the activity of Au-Pd/TiO2 was superior to that of a physical mixture of Au/TiO2 and Pd/TiO2. The present Au-Pd/TiO2-catalyzed transformation of cyclohexylamines proceeds through complex pathways comprising amine dehydrogenation, imine disproportionation, and condensation reactions. The amine dehydrogenation and imine disproportionation reactions are effectively promoted by palladium (not by gold), and the intrinsic catalytic performance of palladium is significantly improved by alloying with gold. One possible explanation of the alloying effect is the formation of electron-poor palladium species that can effectively promote the β-H elimination step in the rate-limiting amine dehydrogenation.
- Taniguchi, Kento,Jin, Xiongjie,Yamaguchi, Kazuya,Nozaki, Kyoko,Mizuno, Noritaka
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p. 2131 - 2142
(2017/03/09)
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- Fullerenes for catalysis: Metallofullerenes in hydrogen transfer reactions
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[60]Fullerene hybrids have successfully been used as catalysts in hydrogen transfer reactions, namely ketone reduction and N-alkylation with alcohols. Due to their poor solubility in polar solvents, these hybrids behave as homogeneous/heterogeneous catalysts that can be mechanically separated and reused several times while the final products do not need chromatographic separation.
- Vidal, Sara,Marco-Martínez, Juan,Filippone, Salvatore,Martín, Nazario
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p. 4842 - 4844
(2017/07/06)
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- Oxidatively Triggered Carbon-Carbon Bond Formation in Ene-amide Complexes
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Ene-amides have been explored as ligands and substrates for oxidative coupling. Treatment of CrCl2, Cl2Fe(PMe3)2, and Cl2Copy4 with 2 equiv of {(2,6-iPr2C6H3)(1-cHexenyl)N}Li afforded pseudosquare planar {3-C,C,N-(2,6-iPr2C6H3)(1-cHexenyl)N}2Cr (1-Cr, 78%), trigonal {(2,6-iPr2C6H3)(1-cHexenyl)N}2Fe(PMe3) (2-Fe, 80%), and tetrahedral {(2,6-iPr2C6H3)(1-cHexenyl)N}2Co(py)2 (3-Co, 91%) in very good yields. The addition of CrCl3 to 1-Cr, and FeCl3 to 2-Fe, afforded oxidatively triggered C-C bond formation as rac-2,2′-di(2,6-iPr2C6H3N - )2dicyclohexane (EA2) was produced in modest yields. Various lithium ene-amides were similarly coupled, and the mechanism was assessed via stoichiometric reactions. Some ferrous compounds (e.g., 2-Fe, FeCl2) were shown to catalyze C-arylation of {(2,6-iPr2C6H3)(1-cHexenyl)N}Li with PhBr, but the reaction was variable. Structural characterizations of 1-Cr, 2-Fe, and 3-Co are reported.
- Jacobs, Brian P.,Wolczanski, Peter T.,Lobkovsky, Emil B.
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supporting information
p. 4223 - 4232
(2016/05/24)
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- Cobalt-Catalyzed N-Alkylation of Amines with Alcohols
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A well-defined nonprecious metal cobalt(II) catalyst based on a pincer PNP ligand has been employed for the efficient N-alkylation of both aromatic and aliphatic amines with alcohols. A subtle change of reaction conditions (simply adding 4 ? molecular sieves) was observed to readily switch the resulting products (amines vs imines) with high chemoselectivity. A range of alcohols and amines including both aromatic and aliphatic substrates were efficiently converted to secondary amines in good-to-excellent yields when 2 mol % cobalt catalyst was used. Additional experiments indicate that a hydrogen-borrowing mechanism is responsible for the tandem acceptorless dehydrogenation/condensation/hydrogenation process.
- Zhang, Guoqi,Yin, Zhiwei,Zheng, Shengping
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p. 300 - 303
(2016/02/03)
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- Coupling MOF-based photocatalysis with Pd catalysis over Pd@MIL-100(Fe) for efficient N-alkylation of amines with alcohols under visible light
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Pd nanoparticles with an average size of 1.7 nm confined inside a MIL-100(Fe) cavity (Pd@MIL-100(Fe)) were prepared via double-solvent impregnation combined with a photoreduction process. Due to efficient coupling of photocatalytic dehydrogenation and Pd-based hydrogenation, the resultant Pd@MIL-100(Fe) showed significantly superior performance in light-induced N-alkylation of amines with alcohols over Pd/MIL-100(Fe), in which larger Pd nanoparticles (6–12 nm) deposited on the external surface of MIL-100(Fe) were prepared via a conventional single-solvent impregnation followed by a similar photoreduction process. Kinetic studies and controlled experiments revealed that the whole N-alkylation reaction is limited by the photocatalytic alcohol-to-aldehyde dehydrogenation reaction. This is the first demonstration of light-induced N-alkylation of amines by alcohols over M/MOFs nanocomposites and also highlights the great potential of using M/MOFs nanocomposites as multifunctional catalysts for light-induced organic syntheses.
- Wang, Dengke,Li, Zhaohui
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p. 151 - 157
(2018/03/29)
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- Synthesis of 3-Sulfonylamino Quinolines from 1-(2-Aminophenyl) Propargyl Alcohols through a Ag(I)-Catalyzed Hydroamination, (2 + 3) Cycloaddition, and an Unusual Strain-Driven Ring Expansion
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We describe herein a silver-catalyzed conversion of 1-(2-aminophenyl)-propargyl alcohols to 4-substituted 3-tosylaminoquinolines using TsN3 as an amino surrogate. Controlled reactions reveal the pathway consisting of Ag(I)-catalyzed 5-exo-dig cyclization, catalyst-free (2 + 3) cycloaddition, and ring-expansive rearrangement via nitrogen expulsion. As a support study, we show that the cyclic enamines in similar conditions produce amidines via a C - C bond migration. (Chemical Equation Presented).
- Kumar, Yalla Kiran,Kumar, Gadi Ranjith,Reddy, Thota Jagadeshwar,Sridhar, Balasubramanian,Reddy, Maddi Sridhar
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p. 2226 - 2229
(2015/05/13)
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- One pot synthesis of cyclohexanone oxime from nitrobenzene using a bifunctional catalyst
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Cyclohexanone oxime is formed from nitrobenzene with 97% yield in a one-pot reaction catalysed by palladium and gold nanoparticles on carbon. The reaction is carried out under hydrogen at 60 °C and the overall transformation involves a multi-step catalysed mechanism from which intermediates and catalytically active species have been identified.
- Rubio-Marques, Paula,Hernandez-Garrido, Juan Carlos,Leyva-Perez, Antonio,Corma, Avelino
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p. 1645 - 1647
(2014/02/14)
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- Solvent-free synthesis of imines via N-alkylation of aromatic amines with alcohols over Co2+-exchanged zeolites
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Co2+-exchanged zeolite catalysts were prepared by an ion-exchange route and firstly applied in the N-alkylation of aromatic amines with alcohols to imines. For the N-alkylation of aniline with benzyl alcohol, the aniline conversion of 89.8 mol% with an imine selectivity of 100% was achieved over Co-13X at 433 K under optimal conditions. The results showed that many factors including the Co loading, the support, the temperature, the alkali, could influence the reactions. Investigations carried out by XRD, SEM and recycling studies indicated that the Co-13X catalyst still remained porous structures of 13X zeolite and possessed a stable catalytic activity.
- Sun,Lu,Wei,Zhou,Xia
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p. 213 - 217
(2013/11/19)
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- Solid base catalyzed highly efficient N-alkylation of amines with alcohols in a solvent-free system
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Different from any other catalytic systems containing transition metals and additives, sodium hydroxide itself was found to be a unique and effective catalyst for the solvent-free synthesis of the secondary amines via the N-alkylation of amines with alcohols. For the reaction of aniline with benzyl alcohol, 99.6 mol% conversion of aniline and 99.5% selectivity of the product were achieved under optimal conditions. Also, high conversion and selectivity could be acquired for the N-alkylations of various amines with alcohols, implying the universality of this methodology. Mechanistic studies revealed that this novel reaction most possibly proceeds with a base-catalyzed mechanism.
- Lu,Sun,Wei,Peng,Zhou,Xia
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- Clean borrowing hydrogen methodology using hydrotalcite supported copper catalyst
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The catalytic activity of Mg-Al hydrotalcite supported copper catalyst was investigated for clean CC and CN bond forming reactions using alcohols as alkylating agent via borrowing hydrogen methodology. The catalyst showed excellent conversion of ketone and amine substrates (71-99%) to alkylated products with high selectivity in alkylation reactions.
- Dixit, Manish,Mishra, Manish,Joshi, Pradyuman A.,Shah, Dinesh O.
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- Modular synthesis of indoles from imines and o-dihaloarenes or o-chlorosulfonates by a Pd-catalyzed cascade process
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A detailed study of the scope of a new Pd-catalyzed synthesis of indolesfrom 1,2-dihaloarenes and o-halobenzene sulfonates and imines is descri bed. The cascade reaction comprises an imine a-arylation ollowed by an intramolecular C-N bond-forming reaction promoted by the same Pd catalyst. The reaction with 1,2-dibromobenzene shows wide scope and allows the introduction of aryl, alkyl, and vinyl substituents at different positions of the five-membered ring of the indole. The regioselective synthesis of indoles substituted in the six-membered ring can be carried out by employing o-dihalobenzene derivatives with two different halogens, taking advantage of the different reactivities of I, Br, and Cl in oxidative addition reactions. This paper also introduces a method for the efficient cleavage of the N-t-butyl group, thus allowing for the preparation of N-H indoles through the same methodology. Finally, the reaction with o-halosulfonates has been studied. The best substrates are o-chlorononaflates, which lead to indoles in very high yield. The reaction is particularlyappropriate for the synthesis of the challenging 6-substituted indoles. In view of the availability of o-chlorophenols, which are direct precur sors of the chlorononaflates, this reaction represents an efficient entry into indoles substituted in the six-membered ring. The concept is illustrated by the preparation of a 4,6-disubstituted indole from naturally occurring anethole.
- Barluenga, Jose,Jimenez-Aquino, Agustin,Aznar, Fernando,Valdes, Carlos
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supporting information; experimental part
p. 4031 - 4041
(2009/09/04)
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- Synthesis and nematicidal activity of 2-(1H-benzo[d]imidazol-2-ylmethyl)-4- aryl-1-thia-4-azaspiro[4.5]decan-3-one
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A series of N-cyclohexylidene-N-phenylamines 3 are prepared by the condensation of cyclohexanone 1 with aryl amine 2, subsequent treatment of 3 with thiomalic acid give the corresponding 2-(3-oxo-4-aryl-1-thia-4-azaspiro[4. 5]dec-2-yl)acetic acid 4, which
- Srinivas,Nagaraj,Reddy, Ch. Sanjeeva
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p. 787 - 791
(2008/12/20)
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- Conformational and structural analysis of exocyclic olefins and ketimines by multinuclear magnetic resonance
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The 1H, 13C, and 15N NMR spectra of 5 exocyclic alkenes and 15 different ketimines obtained from cyclohexanone and derivatives using benzyl bromide and primary amines - are analyzed. Relative stereochemical and preferentia
- Montalvo-Gonzalez, Ruben,Montalvo-Gonzalez, J. Ascencion,Ariza-Castolo, Armando
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experimental part
p. 907 - 912
(2009/05/09)
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- N-substituted imines by the copper-catalyzed N-imination of boronic acids and organostannanes with O-acyl ketoximes
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Catalytic quantities of copper(I) or copper(II) sources catalyze the N-imination of boronic acids and organostannanes through reaction with oxime O-carboxylates under nonbasic conditions. This method tolerates various functional groups and takes place efficiently using aryl, heteroaryl, and alkenyl boronic acids and stannanes.
- Liu, Songbai,Yu, Ying,Liebeskind, Lanny S.
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p. 1947 - 1950
(2008/02/02)
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- Direct and indirect reductive amination of aldehydes and ketones with solid acid-activated sodium borohydride under solvent-free conditions
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A simple and convenient procedure for reductive amination of aldehydes and ketones using sodium borohydride activated by boric acid, p-toluenesulfonic acid monohydrate or benzoic acid as reducing agent under solvent-free conditions is described.
- Byung, Tae Cho,Sang, Kyu Kang
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p. 5725 - 5734
(2007/10/03)
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- In vitro antifungal activity of new series of homoallylamines and related compounds with inhibitory properties of the synthesis of fungal cell wall polymers
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The synthesis, in vitro antifungal evaluation and SAR studies of 101 compounds of the 4-aryl-, 4-alkyl-, 4-pyridyl or -quinolinyl-4-N-arylamino-1-butenes series and related compounds, are reported here. Active structures showed to inhibit (1,3)-β-D-glucan and mainly chitin synthases, enzymes that catalyze the synthesis of the major fungal cell wall polymers.
- Vargas M., Leonor Y.,Castelli, Maria V.,Kouznetsov, Vladimir V.,Urbina G., Juan M.,Lopez, Silvia N.,Sortino, Maximiliano,Enriz, Ricardo D.,Ribas, Juan C.,Zacchino, Susana
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p. 1531 - 1550
(2007/10/03)
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- A simple protocol for direct reductive amination of aldehydes and ketones using potassium formate and catalytic palladium acetate
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A method for direct reductive amination of aldehydes and ketones, including α,β-unsaturated carbonyl compounds, has been developed, which requires potassium formate as reductant and palladium acetate as catalyst. Suitable amines include both primary and secondary aliphatic and aromatic amines.
- Basu, Basudeb,Jha, Satadru,Bhuiyan, Md. Mosharef H.,Das, Pralay
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p. 555 - 557
(2007/10/03)
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- A new protocol for a one-pot synthesis of α-amino phosphonates by reaction of imines prepared in situ with trialkylphosphites
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Imines prepared in situ by reaction of aldehydes and ketones with primary amines in ethereal solution of LiClO4 react readily at ambient temperature with trialkylphosphite to give high yields of α-amino phosphonates.
- Saidi, Mohammad R.,Azizi, Najmedin
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p. 1347 - 1349
(2007/10/03)
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- Sodium borohydride on wet clay: Solvent-free reductive amination of carbonyl compounds using microwaves
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A solvent-flee reductive amination of carbonyl compounds by wet montmorillonite K 10 clay supported sodium borohydride is described; microwave irradiation facilitates the procedure.
- Varma, Rajender S.,Dahiya, Rajender
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p. 6293 - 6298
(2007/10/03)
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- Catalytic Synthesis of Triarylamines
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Condensation along Ullman reaction in the presence of copper catalysts was carried out with para-substituted arylamines and p-iodotoluene to yield the corresponding triarylamines. For preparation of diarylamines was used dehydrogenation of N-cycloalkylanilines and azomethines; diarylamines were obtained through dehydroamination of cycloaliphatic alcohols with anilines.
- Tarasievich,Mikhalevskaya,Kozlov
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p. 1100 - 1102
(2007/10/03)
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- Comparison of the Tautomerization and Hydrolysis of Some Secondary and Tertiary Enamines
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N-Phenylcyclohex-1-en-1-amine, N-(p-chlorophenyl)cyclohex-1-en-1-amine, the N-aryl-2-methylprop-1-en-1-amines, Me2C=CHNLC6H4X, L = H, D, X = H, p-Cl, p-Me, p-MeO, m-NO2, the N-alkyl-2-methylprop-1-en-1-amines, Me2C = CHNDR, R = Me, Et and the (E)-N-alkylprop-1-en-1-amines, MeHC = CHNDR, R = Me, t-Bu, were generated in solution from their N-trimethylsilyl derivatives and characterized by NMR spectroscopy.N-(p-Nitrophenyl)-2-methylprop-1-en-1-amine was isolated from the reaction of isobutyraldehyde and p-nitroaniline, and appreciable amounts (>10percent) of the N-arylcyclohex-1-en-1-amines and N-aryl-2-methylcyclohex-1-en-1-amines were found to be present at equilibrium in DMSO-d6 solution when the aryl group was phenyl, p-chlorophenyl, m-nitrophenyl, or p-nitrophenyl.The kinetics of hydrolysis of all the N-aryl secondary enamines obtained in the above ways were measured in aqueous solution and compared with those of the corresponding N-methyl tertiary enamines.With all enamines there was a region of pH in which kobsd was proportional to 10-pH, and under such conditions it was considered that the rate-determining step was C-protonation.This was supported by the isotope effect kH(1+)/kD(1+) = ca. 3, the observation of general acid catalysis, the much faster rate of hydrolysis of the corresponding imines, and the negative ρ- values.It was found that in the cyclohexenyl series the secondary and tertiary enamines were hydrolyzed at similar rates when the substituents in the aryl group were the same, but in the 2-methylcyclohexenyl and 2-methylpropenyl series the secondary enamines were hydrolyzed much faster than the corresponding tertiary enamines.This was attributed to the tertiary enamines being hindered from attaining the most favorable conformation for p-? conjugation.
- Capon, Brian,Wu, Zhen-Ping
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p. 2317 - 2324
(2007/10/02)
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- Imine-enamine tautomerism in the anils of cyclohexanone and 2-(β-cyanoethyl)cyclohexanone
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The products from the condensation of cyclohexanone and 2-(β-cyanoethyl)cyclohexanone with para- and ortho-disubstituted anilines in 10percent solutions in carbon tetrachloride exist as mixtures of the imine and enamine tautomers.The tautomeric compositio
- Kayukova, L. A.,Erzhanov, K. B.,Umarova, Z. N.
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p. 111 - 119
(2007/10/02)
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- PALLADIUM-CATALYZED COUPLINGS OF N-SUBSTITUTED ISOCYANIDE DICHLORIDES WITH ALKYNYLTIN COMPOUNDS: NEW SYNTHESIS OF DIALKYNYLKETONES
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N-Substituted isocyanide dichlorides were coupled with alkynyltin compounds in the presence of palladium catalyst to produce N-substituted dialkynylimines, of which hydrolysis provides a convenient preparative method of dialkynylketones.
- Ito, Yoshihiko,Inouye, Masahiko,Murakami, Masahiro
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p. 5379 - 5382
(2007/10/02)
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- Selective, Oxophilic Imination of Ketones with Bis(dichloroaluminum) Phenylimide
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Bis(dichloroaluminum) phenylimide, which can be readily prepared from ethylaluminum dichloride and aniline, is shown to be a highly selective iminating agent for aldehydes, ketones, and acid chlorides.Especially the transformation of α,β-unsaturated keton
- Eisch, John J.,Sanches, Ramiro
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p. 1848 - 1852
(2007/10/02)
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- Reduction of Schiff Bases with Isopropyl Alcohol and Aluminum Isopropoxide in the Presence of Raney Nickel
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The reduction of several N-alkyl and N-aryl ketimines to the corresponding secondary amines is described.The reaction, which generally proceeds in high yield, is effected by isopropyl alcohol and aluminium isopropoxide in the presence of Raney nickel.In the absence of the nickel catalyst, that is, under the Meerwein-Ponndorf-Verley conditions, the reaction takes a different route and N-isopropylamines are formed at preference to the direct reduction products.Without the aluminum alkoxide the reduction proceeds only for a small percentage.This reaction, besides offering a new method for the synthesis of secondary amines, represents the first example where the couple aluminum alkoxide/Raney nicel is used in catalytic transfer hydrogenation reactions.
- Botta, Maurizio,Angelis, Francesco De,Gambacorta, Augusto,Labbiento, Lucia,Nicoletti, Rosario
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p. 1916 - 1919
(2007/10/02)
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- Hindered Amines. Synthesis of Hindered Acyclic α-Aminoacetamides
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Hindered amines and their nitroxyl radicals are useful in spin-label studies as nonnucleophilic bases and as stabilizers for polymers against UV degradation.Hindered acyclic α-aminoacetamides (3, R5 = aryl, tert-butyl; R6 = H) can be synthesized from amines, ketones, and chloroform with 50percent sodium hydroxide solution in phase-transfer-catalyzed reactions.Nucleophilic secondary amines will undergo the same reactions while bulky ones fail.Mixed 3 can be prepared from different amines according to their nucleophilicities. 1,1-Dialkyl-2,2-dichlorooxirane (5) is believedto be the reactive intermediate.Imines are sometimes formed as byproducts through the opening of a carbon-carbon bond in the oxirane ring by amines.Thus, tert-butylcyclohexylamine (7) is obtained in 62percent yield after hydrogenation of the crude imine from tert-butylamine, cyclohexanone, and chloroform.
- Lai, John T.
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p. 3671 - 3673
(2007/10/02)
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- New Olefin and Oxiran Syntheses from Carbonyl Compounds, and Diethyl Sodiophosphonate Anions and 1-Aminophosphonate Amino-anions
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Reaction of aromatic aldehydes, and phthalic and thiophthalic anhydrides, with diethyl sodiophosphonate (1) gives the trans-stilbenes (3), 3,3'-biphthalidylidene (30), and 3,3'-bis-(2-thiophthalidylidene) (33).Similar treatment of fluorenone (8) and xanthone (17) with (1) leads to 9,9'-bis(fluororenylidene) (9) and 9,10-dihydro-9-oxophenanthrene-10-spiro-9'-fluorene (10), and to 9,9'-bixanthenylidene (18) and 9,9'-bixanthenyl (19), respectively, but the reaction using anthrone (11) as a carbonyl reagent yields only anthraquinone (12) and anthracene (13).Similar treatment using N-methylisatoic anhydride (34) and N-methylisatin (36) produces NN'-dimethylisoindigo (35).Reaction of benzaldehyde and p-chlorobenzaldehyde with diethyl 1--cyclohexylphosphonate (40) gives mainly corresponding mixtures of trans- (41a,b) and cis-stilbene epoxides (42a,b), while similar treatment of p-nitrobenzaldehyde with (40) produces 4,4'-dinitrostilbene (3e).Reaction of (8) with (40), as well as with (1), gives (9) and (10).The mechanism of formation of these products is discussed.
- Minami, Toru,Matsuzaki, Narihide,Ohshiro, Yoshiki,Agawa, Toshio
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p. 1731 - 1738
(2007/10/02)
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