- N-H Bond Formation in a Manganese(V) Nitride Yields Ammonia by Light-Driven Proton-Coupled Electron Transfer
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A method for the reduction of a manganese nitride to ammonia is reported, where light-driven proton-coupled electron transfer enables the formation of weak N - H bonds. Photoreduction of (saltBu)MnVN to ammonia and a Mn(II) complex has been accomplished using 9,10-dihydroacridine and a combination of an appropriately matched photoredox catalyst and weak Br?nsted acid. Acid-reductant pairs with effective bond dissociation free energies between 35 and 46 kcal/mol exhibited high efficiencies. This light-driven method may provide a blueprint for new approaches to catalytic homogeneous ammonia synthesis under ambient conditions.
- Wang, Dian,Loose, Florian,Chirik, Paul J.,Knowles, Robert R.
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- Vanadium-Catalyzed Dehydrogenation of N-Heterocycles in Water
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In this paper, the dehydrogenation of tetrahydroquinolines using oxovanadium(V) catalysts under mild conditions in water and oxygen atmosphere is described. This catalytic technology was successfully applied to a range of other structurally related N-heterocycles, and a reaction mechanism is proposed.
- Zumbr?gel, Nadine,Sako, Makoto,Takizawa, Shinobu,Sasai, Hiroaki,Gr?ger, Harald
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- Simple and convenient conversion of acridones into 9-unsubstituted acridines via acridanes using borane tetrahydrofuran complex
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A new method for the synthesis of 9-unsubstituted acridines from acridones using mild conditions is described. Various acridines bearing reduction-sensitive group(s) have been synthesized from the corresponding acridones using a two-step procedure that involved a commercially available borane complex reduction followed by an acridane oxidation.
- Desbois, Nicolas,Szollosi, Anna,Maisonial, Aurélie,Weber, Valérie,Moreau, Emmanuel,Teulade, Jean-Claude,Chavignon, Olivier,Blache, Yves,Chezal, Jean Michel
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- Copper-catalyzed aerobic oxidative C-H and C-C functionalization of 1-[2-(Arylamino)aryl]ethanones leading to acridone derivatives
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Efficient copper-catalyzed aerobic oxidative C-H and C-C functionalization of 1-[2-(arylamino)aryl]ethanones leading to acridones has been developed. The procedure involves cleavage of aromatic C-H and acetyl C-C bonds with intramolecular formation of a diarylketone bond. The protocol uses inexpensive Cu(O2CCF3)2 as catalyst, pyridine as additive, and economical and environmentally friendly oxygen as the oxidant, and the corresponding acridones with various functional groups were obtained in moderate to good yields. Acridone synthesis: Efficient copper-catalyzed aerobic oxidative C-H and C-C functionalization of 1-[2-(arylamino)aryl]ethanones leading to acridones has been developed. The procedure involves cleavage of aromatic C-H and acetyl C-C bonds with intramolecular formation of a diarylketone bond (see scheme). The protocol uses inexpensive Cu(O 2CCF3)2 as catalyst, pyridine as additive, and economical and environmentally friendly oxygen as oxidant. The corresponding acridones with various functional groups were obtained in moderate to good yields. Copyright
- Yu, Jipan,Yang, Haijun,Jiang, Yuyang,Fu, Hua
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- A novel flash vacuum pyrolysis route to acridine
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The flash vacuum pyrolysis (FVP) of 5,6,11,12-tetrahydrodibenzo[b,f]azocine (6) gives a good yield (75%) of acridine (7). A mechanism for this novel reaction is presented.
- Trahanovsky, Walter S.,Lee, Suk-Kyu
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- Gossypol clathrates: Structure and thermal behavior of the gossypol acridine complex
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The natural compound gossypol forms a stable clathrate with acridine. The composition of the clathrate is C30H30O 8·0.5C13H9N. The unit cell is monoclinic, C2/c space group, a = 11.3213(3) A, b = 30.5957(13) A, c = 17.0824(4) A, γ = 94.153(2)°, V = 5901.5(3) A3, M = 1153.24, Z = 8, dx = 1.369 g/cm3, and R = 0.0413 for 4726 reflections. The structure of the clathrate allows one to refer this compound to the ethyl acetate isomorphic host-guest group of gossypol complexes.
- Khonkeldieva,Talipov,Izotova,Tilyakov,Ibragimov,Kurtaliev
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- A Simple Route to C-Functionalised Azaxylylenes and Diazaxylylenes
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o-Lithiation of t-butoxycarbonylaniline and 4-t-butoxycarbonylaminopyridine followed by reaction with aldehydes gives t-butoxycarbonylamino alcohols which are converted into azaxylylenes and diazaxylylenes on flash pyrolysis.
- Fishwick, Colin W. G.,Storr, Richard C.,Manley, Paul W.
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- Oxidation of N-methyl-9-t-butylacridane by iodosylbenzene catalyzed by tetrakis(pentafluorophenyl) porphyrin iron(III). A tool to investigate the mechanism of the oxidative N-demethylation of aromatic tertiary amines
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The PhIO promoted oxidation of N-methyl-9-t-butylacridane (1) catalyzed by tetrakis(pentafluorophenyl) porphyrin iron(III) leads first to 9-t- butylacridane and then to acridine. It is suggested that 1 can represent a reliable machanistic probe to detect the intervention of radical cations in the oxidation of aromatic amines.
- Baciocchi, Enrico,Lapi, Andrea
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- Flash Vacuum Pyrolysis of o-Azidodiphenylmethanes. Nitrene Insertions with Temperature Variability
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The decomposition of o-azidodiphenylmethanes by flash vacuum pyrolysis (f.v.p.) (350 - 700 deg C) gives acridan and acridine in contrast with the production of 10H-azepinoindole at lower temperatures in solution; similar f.v.p. treatment of 10H-azepinoindole gives some of the tautomeric 6H-azepinoindole.
- Hicks, Martin G.,Jones, Gurnos
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- Photocatalytic degradation of antiepileptic drug carbamazepine with bismuth oxychlorides (BiOCl and BiOCl/AgCl composite) in water: Efficiency evaluation and elucidation degradation pathways
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The heterogeneous photocatalytic degradation of carbamazepine (CBZ) was investigated in the presence of BiOCl/AgCl composite photocatalyst under simulated sunlight irradiation in water. BiOCl/AgCl composite showed higher photocatalytic activity than pure BiOCl for CBZ degradation. The photocatalytic mechanism analysis was based on byproducts identification by LC–MS-QTof and active species trapping or inhibiting experiments. The results revealed that the first step of the transformation mainly results in an electron transfer implying positive holes and to a lesser extent in hydroxyl radical's involvement. The enhanced photocatalytic performance of BiOCl/AgCl was proved to be related to the suitable conduction and valence band interaction that extends optical response range but also improves the efficient separation of photoinduced electron-hole pairs. BiOCl/AgCl composite totally removed CBZ from natural surface water after 30?min irradiation, suggesting its potential application to wastewater treatments. Eight intermediate products were identified demonstrating that CBZ transformation occurs through two main routes from CBZ radical cation, hydroxylation of ring (aromatic or seven membered rings), followed by further oxidation, rearrangement ring and hydroxylation.
- Meribout, Rayene,Zuo, Ying,Khodja, Amina Amine,Piram, Anne,Lebarillier, Stéphanie,Cheng, Jiushan,Wang, Cong,Wong-Wah-Chung, Pascal
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- Nitrogen Analogues of o-Xylylenes
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The gas-phase pyrolysis of o-hydroxymethylanilines provides simple, one-step syntheses of acridines, acridones, and quinoline derivatives.The ease with which nitrogen analogues of o-xylylenes are formed during pyrolysis suggests that the methodology currently used in the synthetic applications of benzocyclobutenes can be employed with these azo-o-xylylenes to yield a variety of heterocycles and polycyclic amines.
- Mao, Yuh-lin,Boekelheide, V.
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- New Gas Phase Reactions of Substituted Benzyl, Phenylaminyl, and Phenoxyl Radicals. Rearrangements to Fused 5- and 6-Membered Heterocyclic Systems
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Flash vacuum pyrolysis studies of substituted benzyl, phenylaminyl, and phenoxyl radicals have revealed three new classes of reactions: formation of five-membered ring products via intramolecular abstracion of an aromatic hydrogen atom, formation of six-membered rings via spirodienyl radical intermediates, and isomerisation of o-phenoxybenzyl into o-benzylphenoxyl radicals and vice versa.
- Cadogan, J. I. G.,Hickson, Clare L.,Hutchison, H. Susan,McNab, Hamish
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- Method for realizing oxidative dehydrogenation of nitrogen-containing heterocyclic ring by using biomass-based carbon material
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The invention provides a method for realizing oxidative dehydrogenation of a nitrogen-containing heterocyclic ring by using a biomass-based carbon material, and belongs to the field of organic synthesis. According to the method, the raw materials of the biomass-based carbon material comprise wheat, sorghum, rice, corn straw, wheat straw, peanut shells, sesame shells, bean shells and the like, and are crushed and then ground into powder, the powder is fully mixed with an inorganic alkali, and calcination is performed in an inert gas atmosphere to prepare the biomass-based carbon material; and by using air as an oxygen source, at a temperature of 50-120 DEG C, oxidative dehydrogenation of nitrogen-containing heterocyclic compounds to synthesize quinoline compounds, isoquinoline compounds, acridine compounds, quinazoline compounds, indole compounds, imine compounds, and even quinoline compounds with pharmaceutical activity can be achieved. According to the present invention, easily available wheat flour is adopted as a raw material to prepare a non-metal catalyst, the alkali is not added during the reaction process, and a remarkable industrial application prospect is achieved.
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Paragraph 0010-0011; 0032-0033
(2021/06/26)
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- Visible-light-mediated organoboron-catalysed metal-free dehydrogenation of N-heterocycles using molecular oxygen
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The surge of photocatalytic transformation not only provides unprecedented synthetic methods, but also triggers the enthusiasm for more sustainable photocatalysts. On the other hand, oxygen is an ideal oxidant in terms of atom economy and environmental friendliness. However, the poor reactivity of oxygen at the ground state makes its utilization challenging. Herein, a visible-light-induced oxidative dehydrogenative process is disclosed, which uses an organoboron compound as the photocatalyst and molecular oxygen as the sole oxidant.Viathis approach, an array of N-heterocycles have been accessed under metal-free mild conditions, in good to excellent yields.
- Wei, Lanfeng,Wei, Yu,Xu, Liang,Zhang, Jinli
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supporting information
p. 4446 - 4450
(2021/06/30)
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- Decarboxylation of Aromatic Carboxylic Acids by the Prenylated-FMN-dependent Enzyme Phenazine-1-carboxylic Acid Decarboxylase
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Phenazine-1-carboxylic acid decarboxylase (PhdA) is a member of the expanding class of prenylated-FMN-dependent (prFMN) decarboxylase enzymes. These enzymes have attracted interest for their ability to catalyze (de)carboxylation reactions on aromatic rings and conjugated double bonds. Here we describe a method to reconstitute PhdA with prFMN that produces an active and stable form of the holo-enzyme that does not require prereduction with dithionite for activity. We establish that oxidized phenazine-1-carboxylate (PCA) is the substrate for decarboxylation, withkcat= 2.6 s-1andKM= 53 μM. PhdA also catalyzes the much slower exchange of solvent deuterium into the product, phenazine, with an apparent turnover number of 0.8 min-1. The enzyme was found to catalyze the decarboxylation of a broad range of polyaromatic carboxylic acids, including anthracene-1-carboxylic acid. Previously described prFMN-dependent aromatic (de)carboxylases have utilized electron-rich phenolic or heterocyclic molecules as substrates. PhdA extends the substrate range of prFMN-dependent (de)carboxylases to electron-poor and unfunctionalized aromatic systems, suggesting that it may prove a useful catalyst for the regioselective (de)carboxylation of otherwise unreactive aromatic molecules.
- Datar, Prathamesh M.,Marsh, E. Neil G.
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p. 11723 - 11732
(2021/09/28)
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- Clean protocol for deoxygenation of epoxides to alkenes: Via catalytic hydrogenation using gold
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The epoxidation of olefin as a strategy to protect carbon-carbon double bonds is a well-known procedure in organic synthesis, however the reverse reaction, deprotection/deoxygenation of epoxides is much less developed, despite its potential utility for the synthesis of substituted olefins. Here, we disclose a clean protocol for the selective deprotection of epoxides, by combining commercially available organophosphorus ligands and gold nanoparticles (Au NP). Besides being successfully applied in the deoxygenation of epoxides, the discovered catalytic system also enables the selective reduction N-oxides and sulfoxides using molecular hydrogen as reductant. The Au NP catalyst combined with triethylphosphite P(OEt)3 is remarkably more reactive than solely Au NPs. The method is not only a complementary Au-catalyzed reductive reaction under mild conditions, but also an effective procedure for selective reductions of a wide range of valuable molecules that would be either synthetically inconvenient or even difficult to access by alternative synthetic protocols or by using classical transition metal catalysts. This journal is
- Fiorio, Jhonatan L.,Rossi, Liane M.
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p. 312 - 318
(2021/01/29)
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- Iron(II)-Catalyzed Aerobic Biomimetic Oxidation of N-Heterocycles
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Herein, an iron(II)-catalyzed biomimetic oxidation of N-heterocycles under aerobic conditions is described. The dehydrogenation process, involving several electron-transfer steps, is inspired by oxidations occurring in the respiratory chain. An environmentally friendly and inexpensive iron catalyst together with a hydroquinone/cobalt Schiff base hybrid catalyst as electron-transfer mediator were used for the substrate-selective dehydrogenation reaction of various N-heterocycles. The method shows a broad substrate scope and delivers important heterocycles in good-to-excellent yields.
- Manna, Srimanta,Kong, Wei-Jun,B?ckvall, Jan-E.
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supporting information
p. 13725 - 13729
(2021/09/08)
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- Synthesis of xanthones, thioxanthones and Acridones by a metal-free photocatalytic oxidation using visible light and molecular oxygen
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9H-Xanthenes, 9H-thioxanthenes and 9,10-dihydroacridines can be easily oxidized to the corresponding xanthones, thioxanthones and acridones, respectively, by a simple photo-oxidation procedure carried out using molecular oxygen as oxidant under the irradiation of visible blue light and in the presence of riboflavin tetraacetate as a metal-free photocatalyst. The obtained yields are high or quantitative.
- Chinchilla, Rafael,Torregrosa-Chinillach, Alejandro
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- Aerobic Dehydrogenation of N-Heterocycles with Grubbs Catalyst: Its Application to Assisted-Tandem Catalysis to Construct N-Containing Fused Heteroarenes
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An aerobic dehydrogenation of nitrogen-containing heterocycles catalyzed by Grubbs catalyst is developed. The reaction is applicable to various nitrogen-containing heterocycles. The exceptionally high functional group compatibility of this method was confirmed by the oxidation of an unprotected dihydroindolactam V to indolactam V. Furthermore, by taking advantage of the oxygen-mediated structural change of the Grubbs catalyst, we integrated ring-closing metathesis and subsequent aerobic dehydrogenation to develop the novel assisted-tandem catalysis using molecular oxygen as a chemical trigger. The utility of the assisted-tandem catalysis was demonstrated by the concise synthesis of N-containing fused heteroarenes including a natural antibiotic, pyocyanine.
- Kawauchi, Daichi,Noda, Kenta,Komatsu, Yoshiyuki,Yoshida, Kei,Ueda, Hirofumi,Tokuyama, Hidetoshi
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supporting information
p. 15793 - 15798
(2020/10/12)
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- 2-Aminobenzaldehyde, a common precursor to acridines and acridones endowed with bioactivities
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By starting from a common substrate, 2-aminobenzaldehyde, both acridines and acridones were prepared. The former were generated in high yields by copper-catalyzed N-arylation followed by acid-mediated cyclization while the latter were obtained by double copper-catalyzed N-arylation followed by cyclization under the same reaction conditions. Moreover, acridine was subjected to deprotometalation by recourse to a lithium-zinc base and converted to the corresponding 4-iodo derivative, which was involved in copper-catalyzed couplings with pyrrolidinone and pyrazole. Finally, addition of pyrazole, indole and carbazole onto the 9 position of bare acridine was improved. While moderate biological activity was noticed in melanoma cells growth inhibition, the newly prepared compounds feature interesting photophysical properties which were evaluated in a preliminary study.
- Bentabed-Ababsa, Ghenia,Dorcet, Vincent,Erb, William,Mongin, Florence,Mongin, Olivier,Picot, Laurent,Roisnel, Thierry,Thiéry, Valérie,Zeghada, Sarah
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- MnOx/catechol/H2O: A cooperative catalytic system for aerobic oxidative dehydrogenation of N-heterocycles at room temperature
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Amorphous manganese oxide doped by Na+ ion (Na-AMO) was successfully prepared and found to be an efficient heterogeneous catalyst in aerobic oxidative dehydrogenation of N-heterocycles, cooperate with catechol. Na-AMO was fully characterized by XRD, XPS BET H2-TPR, CO2-TPD FT-IR, TEM, SEM and had rich amounts of surface absorbed active oxygen species which are responsible for superior catalytic performance. The synergistic interaction between Na-AMO and catechol makes catalytic system efficient and tolerant, which offers various N-heterocycles in good to excellent yields under mild conditions.
- Tang, Tao,Bi, Xiuru,Meng, Xu,Chen, Gexin,Gou, Mingxia,Liu, Xiang,Zhao, Peiqing
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- Visible-Light-Promoted Efficient Aerobic Dehydrogenation of N-Heterocycles by a Tiny Organic Semiconductor Under Ambient Conditions
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An efficient reusable catalytic system has been developed based on perylene diimide (PDI) organic semiconductor for the aerobic dehydrogenation of N-heterocycles with visible light. This practical catalytic system without any additives proceeds under ambient conditions. The minute aggregates of PDI molecules on the surface of SiO2 nanospheres form tiny organic semiconductors, resulting in high-efficiency photo-oxidative activity. Notably, the robustness of this method is demonstrated by the synthesis of a wide range of N-heteroarenes, gram-scale experiments as well as reusability tests.
- Su, Chenliang,Yu, Kunyi,Zhang, Hanjie,Zhu, Yongfa
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supporting information
p. 1956 - 1960
(2020/04/10)
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- Aerobic oxidative dehydrogenation of N-heterocycles over OMS-2-based nanocomposite catalysts: Preparation, characterization and kinetic study
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OMS-2-based nanocomposites doped with tungsten were prepared for the first time and their remarkably enhanced catalytic activity and recyclability in aerobic oxidative dehydrogenation of N-heterocycles were examined in detail. Many tetrahydroquinoline derivatives and a broad range of other N-heterocycles could be tolerated by the catalytic system using a biomass-derived solvent as a reaction medium. Newly generated mixed crystal phases, noticeably enhanced surface areas and labile lattice oxygen of the OMS-2-based nanocomposite catalysts might contribute to their excellent catalytic performance. Moreover, a kinetic study was extensively performed which concluded that the dehydrogenation of 1,2,3,4-tetrahydroquinoline is a first-order reaction, and the apparent activation energy is 29.66 kJ mol-1
- Bi, Xiuru,Tang, Tao,Meng, Xu,Gou, Mingxia,Liu, Xiang,Zhao, Peiqing
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p. 360 - 371
(2020/02/04)
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- METHOD OF PRODUCING DIAMINES AND POLYAMINES OF THE DIPHENYLMETHANE SERIES
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The invention relates to a method for producing diamines and polyamines of the diphenylmethane series, by condensing aniline and formaldehyde followed by an acid-catalysed rearrangement at different production capacities with alteration of the isomer composition in the resulting diamines of the diphenylmethane series (altering the 2,4′-MDA content). Adapting the molar ratios of the total used aniline to the total used formaldehyde and of the total used acid catalyst to the total used aniline, and adapting the reaction temperature, allows the rearrangement reaction to be fully completed despite the change in dwell time inevitably associated with a change in production capacity, and allows the formation of undesired by-products to be avoided as far as possible; the intended modification to binuclear content is likewise achieved.
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Paragraph 0160-0161
(2020/03/28)
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- METHOD OF PRODUCING DIAMINES AND POLYAMINES OF THE DIPHENYLMETHANE SERIES
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The invention relates to a method for producing diamines and polyamines of the diphenylmethane series, by condensing aniline and formaldehyde followed by an acid-catalysed rearrangement at different production capacities with alteration of the content of diamines of the diphenylmethane series (altering the binuclear content). Adapting the molar ratio of the total used aniline to the total used formaldehyde and adapting the reaction temperature allows the rearrangement reaction to be fully completed despite the change in dwell time inevitably associated with a change in production capacity, and allows the formation of undesired by-products to be avoided as far as possible; the intended modification to binuclear content is likewise achieved.
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Paragraph 0168-0170
(2020/05/02)
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- Hydrogenation/dehydrogenation of N-heterocycles catalyzed by ruthenium complexes based on multimodal proton-responsive CNN(H) pincer ligands
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Ru complexes based on lutidine-derived pincer CNN(H) ligands having secondary amine side donors are efficient precatalysts in the hydrogenation and dehydrogenation of N-heterocycles. Reaction of a Ru-CNN(H) complex with an excess of base produces the formation of a Ru(0) derivative, which is observed under catalytic conditions.
- álvarez, Eleuterio,Hernández-Juárez, Martín,López-Serrano, Joaquín,Paneque, Margarita,Rendón, Nuria,Sánchez, Práxedes,Santos, Laura L.,Suárez, Andrés
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supporting information
p. 9583 - 9587
(2020/07/30)
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- Regiodivergent C-H Alkylation of Quinolines with Alkenes by Half-Sandwich Rare-Earth Catalysts
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The regiodivergent catalysis of C-H alkylation with alkenes is of great interest and importance but has remained hardly explored to date. We report herein the first regiodivergent C-H alkylation of quinolines with alkenes by half-sandwich rare-earth catal
- Lou, Shao-Jie,Zhang, Liang,Luo, Yong,Nishiura, Masayoshi,Luo, Gen,Luo, Yi,Hou, Zhaomin
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supporting information
p. 18128 - 18137
(2020/12/02)
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- CONVERSION OF TETRAHYDROQUINOLINE DERIVATIVES TO QUINOLINE USING AZOCOMPOUND
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The present invention relates to a method of converting tetrahydroquinoline derivatives into quinoline using an azo compound and, more specifically, to a conversion method which is performed in a deuterium chloroform (CDCl_3) or chloroform (CHCl_3) solution including dialkyl azodicarboxylate, which is a method of producing quinoline through a dehydrogenation reaction of 1,2,3,4-tetrahydroquinoline. According to the present invention, a dehydrogenation reaction rate is dependent on the electronic and steric properties of used dialkyl azodicarboxylate; and chloroform shows better results than other substances in solvents screened with diethyl azodicarboxylate. Various types of 1,2,3,4-tetrahydroquinoline undergo the dehydration reaction of the present invention to produce the corresponding quinoline in a yield of at least 90%; and diethyl hydrazo dicarboxylate, which is a reduced form of diethyl azodicarboxylate, is readily separated and recyclable.COPYRIGHT KIPO 2020
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Paragraph 0041-0042; 0098; 0112-0116
(2020/03/10)
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- Electrochemical Deoxygenation of N-Heteroaromatic N -Oxides
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An electrochemical method for the deoxygenation of N-heteroaromatic N -oxide to give the corresponding N-heteroaromatics has been developed. Several classes of N-heterocycles such as pyridine, quinoline, isoquinoline, and phenanthridine are tolerated. The electrochemical reactions proceed efficiently in aqueous solution without the need for transition-metal catalysts and waste-generating reducing reagents.
- Xu, H.-C.,Xu, P.
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supporting information
p. 1219 - 1221
(2019/06/08)
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- Potassium tert-Butoxide-Promoted Acceptorless Dehydrogenation of N-Heterocycles
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Potassium tert-butoxide-promoted acceptorless dehydrogenation of N-heterocycles was efficiently realized for the generation of N-heteroarenes and hydrogen gas under transition-metal-free conditions. In the presence of KOtBu base, a variety of six- and five-membered N-heterocyclic compounds efficiently underwent acceptorless dehydrogenation to afford the corresponding N-heteroarenes and H2 gas in o-xylene at 140 °C. The present protocol provides a convenient route to aromatic nitrogen-containing compounds and H2 gas. (Figure presented.).
- Liu, Tingting,Wu, Kaikai,Wang, Liandi,Yu, Zhengkun
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supporting information
p. 3958 - 3964
(2019/08/01)
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- Room temperature catalytic dehydrogenation of cyclic amines with the liberation of H2 using water as a solvent
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Catalytic dehydrogenation of cyclic amines, in particular partially saturated N-heterocycles to N-heterocyclic arenes, with the removal of molecular hydrogen as the sole byproduct in water is reported. This dehydrogenation reaction proceeds smoothly under very mild and benign conditions and operates at room temperature. This distinctive reactivity has been achieved under dual catalytic conditions by merging the visible-light active [Ru(bpy)3]2+ as the photoredox catalyst and a newly synthesized cobalt complex as the proton-reduction catalyst. A detailed mechanistic study (control experiments, electrochemical studies, UV-visible experiments) is presented for the present dual catalysis.
- Sahoo, Manoj K.,Balaraman, Ekambaram
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supporting information
p. 2119 - 2128
(2019/04/26)
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- Preparing method of acridine
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The invention relates to a preparing method of acridine. The method includes the following step of evenly mixing 9-carboxyl acridine, a catalyst and ligand in an organic solvent for the reaction for 1-8 hours at 140-200 DEG C to obtain the acridine, wherein the ligand is at least one of N,N'-dimethylpiperazine, triethylamine, phenanthroline, substituted phenanthroline, N,N,N',N'-tetramethylethylenediamine, N,N'-dimethylaniline and N,N-diisopropylethylamine. According to the preparing method of the acridine, the acridine is synthesized through one step with 9-carboxyl acridine as the raw material, the reaction is carried out with the presence of the catalyst and the ligand, the reaction process is mild and easy to control, the product is high in purity and yield, the industrial manufacturing cost of the acridine is remarkably reduced, and the good industrial application value is realized.
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Paragraph 0017-0041
(2019/08/20)
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- Method for preparing acridine derivative
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The invention relates to a method for preparing an acridine derivative, and specifically relates to a method for preparing the acridine derivative from an organic azide compound and a benzene compoundunder the action of an acid. According to the method disclosed by the invention, no transition metal catalyst is used, and the acridine derivative with an anthracene structure is obtained from a simple and easily-available raw material through simple operation steps.
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Paragraph 0014-0018
(2019/07/16)
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- A Reusable Cobalt Catalyst for Reversible Acceptorless Dehydrogenation and Hydrogenation of N-Heterocycles
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The development of robust catalytic systems based on base-metals for reversible acceptorless dehydrogenation (ADH) and hydrogenation of feedstock chemicals is very important in the context of ‘hydrogen storage’. Herein, we report a highly efficient reusable cobalt-based heterogeneous catalyst for reversible dehydrogenation and hydrogenation of N-heterocycles. Both the ADH and the hydrogenation processes operate under mild, benign conditions.
- Jaiswal, Garima,Subaramanian, Murugan,Sahoo, Manoj K.,Balaraman, Ekambaram
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p. 2449 - 2457
(2019/05/10)
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- Efficient dehydrogenation of 1,2,3,4-tetrahydroquinolines mediated by dialkyl azodicarboxylates
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Various dialkyl azodicarboxylates were investigated for the dehydrogenation of 1,2,3,4-tetrahydroquinolines to quinolines. The dehydrogenation rates varied according to the electronic and steric nature of the used dialkyl azodicarboxylates. Among solvents screened with diethyl azodicarboxylate, chloroform exhibited superior results to others. A variety of 1,2,3,4-tetrahydroquinolines underwent the present dehydrogenation to produce the corresponding quinolines. Diethyl hydrazodicarboxylate, which is a reduced species of diethyl azodicarboxylate, was easily separated for recycle.
- Bang, Saet Byeol,Kim, Jinho
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supporting information
p. 1291 - 1298
(2018/04/05)
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- CO2-Catalyzed Efficient Dehydrogenation of Amines with Detailed Mechanistic and Kinetic Studies
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CO2-catalyzed dehydrogenation of amines has been achieved under photocatalytic conditions. With this concept, various amines have been selectively dehydrogenated to the corresponding imines in the presence of different functional groups such as nitrile, nitro, ester, halogen, ether, thioether, and carbonyl or carboxylic acid moieties. At the end, the CO2-catalyzed synthesis of pharmaceutical drugs has been achieved. The CO2 radical has been detected by EPR spectroscopy using DMPO, and the mechanism of this reaction is proposed on the basis of DFT calculations and experimental evidence.
- Riemer, Daniel,Schilling, Waldemar,Goetz, Anne,Zhang, Yu,Gehrke, Sascha,Tkach, Igor,Hollóczki, Oldamur,Das, Shoubhik
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p. 11679 - 11687
(2018/11/23)
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- Nitrogen-Iodine Exchange of Diaryliodonium Salts: Access to Acridine and Carbazole
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A nitrogen-iodine exchange protocol of diaryliodonium salts with sodium azide salt is developed for general construction of significant functional acridines and carbazoles, in which introduction of nitrogen at a late stage was successfully established avoiding heteroatom incompatibility. Inorganic sodium azide served as the sole nitrogen atom source in this transformation. The diversiform functional acridines and carbazoles were comprehensively achieved through annulated diaryliodonium salts, respectively. Notably, Acridine orange (a fluorescent indicator for cell lysosomal dye) and Carprofen (a nonsteroidal anti-inflammatory drug) were efficiently established through this protocol.
- Wang, Ming,Fan, Qiaoling,Jiang, Xuefeng
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p. 216 - 219
(2018/01/17)
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- Synthesis of Acridines from o-Aminoaryl Ketones and Arylboronic Acids by Copper Trifluoroacetate-Mediated Relay Reactions
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An efficient and practical method for the synthesis of medicinally important acridines from readily available o-aminoaryl ketones and arylboronic acids was developed using copper(II)-mediated relay reactions that involve intermolecular Chan-Lam cross-coupling and subsequent intramolecular Friedel-Crafts-type reactions. A sole promoter, i.e., Cu(OTf)2, was used; therefore, strongly acidic and basic conditions, nonreadily available or expensive substrates, additives, and noble-metal catalysts were not needed.
- Wu, Hao,Zhang, Zhiguo,Ma, Nana,Liu, Qingfeng,Liu, Tongxin,Zhang, Guisheng
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p. 12880 - 12886
(2018/10/09)
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- Rh(III)-catalyzed synthesis of unsymmetrical acridines from aldehydes and azides using transient directing strategy in biomass-derived γ-valerolactone
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An Rh(III)-catalyzed synthesis of unsymmetrical acridines from aldehydes and azides through bilateral cyclization process in biomass-derived γ-valerolactone has been developed. The in situ-generated imino directing group (DG) from aldehyde and catalytic a
- Shen, Jun,Liu, Xi,Wang, Liang,Chen, Qun,He, Mingyang
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p. 1354 - 1362
(2018/04/05)
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- Syntheses of Acridones via Copper(II)-Mediated Relay Reactions from o-Aminoacetophenones and Arylboronic Acids
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The reaction of o-aminoacetophenones and arylboronic acids catalyzed by copper(II) salts in the presence of pyridine under an O2 atmosphere provides a general and efficient one-pot preparation of biologically interesting acridones. This relay reaction comprises an intermolecular Suzuki cross-coupling, intramolecular oxidative C(sp3)-H amination, and C(sp2)-H activation with simultaneous rearrangement of the generated isatin intermediates. This strategy tolerates both electron-donating and -withdrawing functionalities to afford various acridones in good to excellent yields.
- Wu, Hao,Zhang, Zhiguo,Liu, Qingfeng,Liu, Tongxin,Ma, Nana,Zhang, Guisheng
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supporting information
p. 2897 - 2901
(2018/05/29)
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- Controlling Ligand Exchange through Macrocyclization
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Ligand exchange at a sterically hindered palladium center was investigated for six different ligands. The palladium atom was coordinated to a tridentate, NNN pincer bis(amido)pyridine macrocycle to produce a square-planar complex, in which an acetonitrile molecule occupies one of the coordination sites. Kinetic studies showed that ligand exchange at the palladium center proceeds through an associative mechanism and, as a consequence, is impeded by the small size of the metallomacrocycle cavity. The ligand-exchange rate on the palladium center between acetonitrile and six different ligands has been investigated and compared to the exchange rate on the corresponding open form. Our results demonstrate that macrocyclization of ligands is a way to modify the rate of guest exchange in a square-planar metal complex.
- Carta, Veronica,Mehr, S. Hessam M.,Maclachlan, Mark J.
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supporting information
p. 3243 - 3253
(2018/03/25)
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- Nitrogen anthracene class compound and its synthetic method and application (by machine translation)
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The invention discloses a formula (2) shown in nitrogen anthracene class of compound and its synthetic method, high Iodized salt as reaction raw material, in the inorganic nitrogen reagent, additive, water, alkali, under the action of the metal catalyst, in the 80 - 150 °C conditions, reacts in a solvent 12 - 60 hours to obtain various nitrogen anthracene class compounds. The invention by post method of introducing nitrogen atoms, to avoid the early stage in the reaction of the nitrogen heterocyclic to metal catalyst of the reaction conditions such as not compatibility; in addition, high Iodized salt in the full utilization of the two aryl, shows that the method of the invention atom economy. Prepared by the method of the invention can be further applied [...] compound of the fluorescent indicator acridine orange synthesis. (by machine translation)
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Paragraph 0039-0042
(2018/05/16)
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- Oxidation Potential Tunable Organic Molecules and Their Catalytic Application to Aerobic Dehydrogenation of Tetrahydroquinolines
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In this work, oxidation potential tunable organic molecules, alkyl 2-phenyl hydrazocarboxylates, were disclosed. The exquisite tuning of their oxidation potentials facilitated a catalytic dehydrogenation of 1,2,3,4-tetrahydroquinolines in the presence of Mn(Pc) and O2.
- Jung, Dahyeon,Jang, Seol Heui,Yim, Taeeun,Kim, Jinho
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supporting information
p. 6436 - 6439
(2018/10/15)
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- Rh(III)-Catalyzed bilateral cyclization of aldehydes with nitrosos toward unsymmetrical acridines proceeding with C-H functionalization enabled by a transient directing group
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A Rh(iii)-catalyzed bilateral cyclization was developed for the efficient construction of acridines proceeding with C-H functionalization whereby in situ formation and removal of an imino transient directing group in the presence of catalytic amount of BnNH2 are achieved. In this transformation, a sequential Rh(iii)-catalyzed C-H amination, cyclization, and aromatization process was involved.
- Hu, Weiming,Zheng, Qingheng,Sun, Song,Cheng, Jiang
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supporting information
p. 6263 - 6266
(2017/07/07)
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- Organo-Photoredox Catalyzed Oxidative Dehydrogenation of N-Heterocycles
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We report here for the first time the catalytic oxidative dehydrogenation of N-heterocycles by a visible-light organo-photoredox catalyst with low catalyst loading (0.1–1 mol %). The reaction proceeds efficiently under base- and additive-free conditions with ambient air at room temperature. The utility of this benign approach is demonstrated by the synthesis of various pharmaceutically relevant N-heteroarenes such as quinoline, quinoxaline, quinazoline, acridine, and indole.
- Sahoo, Manoj K.,Jaiswal, Garima,Rana, Jagannath,Balaraman, Ekambaram
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supporting information
p. 14167 - 14172
(2017/10/16)
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- Palladium Nanoparticles Stabilized by Metal–Carbon Covalent Bonds as an Expeditious Catalyst for the Oxidative Dehydrogenation of Nitrogen Heterocycles
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The first method for the dehydrogenation of nitrogen heterocycles catalyzed by a palladium nanocatalyst was developed. Carbon–metal covalent-bond-stabilized nanoparticles were found to be efficient for the dehydrogenation process in the presence of tert-butyl hydroperoxide. A variety of N-heterocycles were transformed into functionalized quinolines in medium to excellent yields in water as the solvent under mild conditions by a simple operation.
- Sun, Xiao-Tao,Zhu, Jie,Xia, Yun-Tao,Wu, Lei
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p. 2463 - 2466
(2017/07/12)
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- MAGNETICALLY SEPARABLE IRON-BASED HETEROGENEOUS CATALYSTS FOR DEHYDROGENATION OF ALCOHOLS AND AMINES
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The present invention discloses an iron-based nitrogen doped graphene catalyst, process for preparation thereof and use of said catalyst in oxidant-free catalytic dehydrogenation of alcohols and amines to the corresponding carbonyl compounds, amines and N-heterocylic compounds with extraction of molecular hydrogen as the only by-product.
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Page/Page column 19; 20; 21; 23
(2016/12/22)
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- Method for preparing acridine with o-nitrobenzaldehyde and cyclohexanol serving as raw materials
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The invention relates to a method for preparing acridine compounds with o-nitrobenzaldehyde compounds and cyclohexanol compounds serving as raw materials. The structural formula of the prepared acridine compound is shown in an abstract drawing, R1, R2, R3, R4, R5, R6, R7 and R8 are hydrogen atoms, alkyl, aryl, halogen, alkoxy, aryloxy trifluoromethyl and the like, and R9 is hydrogen atoms, alkyl, aryl and the like. The method for preparing the acridine compounds comprises the step that a reaction system formed by the o-nitrobenzaldehyde compounds, the cyclohexanol compounds, a catalyst and a solvent reacts for 1-24 hours at the temperature of 130 DEG C to 180 DEG C. After the reaction is finished, kieselguhr is used for filtering, an organic solvent is used for washing and concentration, column chromatography extraction is carried out, the acridine compounds are obtained, and the yield ranges from 30% to 70%. The catalyst is a ruthenium catalyst represented by trisruthenium chloride, an iron catalyst represented by 1,1'-bis(diphenylphosphine) ferrocene and the like.
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Paragraph 0010
(2016/11/14)
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- A Convenient Procedure for the Oxidative Dehydrogenation of N-Heterocycles Catalyzed by FeCl2/DMSO
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A convenient catalytic procedure has been developed for the oxidative dehydrogenations of N-heterocycles. Combining catalytic FeCl2 with DMSO yields a catalyst that promotes the dehydrogenation of tetrahydroquinolines and related heterocycles under 1 bar of O2, affording the corresponding N-heteroaromatic products in moderate yields.
- Zhou, Weiyou,Taboonpong, Piyada,Aboo, Ahmed Hamdoon,Zhang, Lingjuan,Jiang, Jun,Xiao, Jianliang
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supporting information
p. 1806 - 1809
(2016/07/16)
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- Preparation method of multi-functional group acridine compound and derivative thereof
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The present invention relates to a preparation method of a multi-functional group acridine compound and a derivative thereof. According to the present invention, specifically a bisphosphine ligand and palladium complex catalyzed series connection coupling/cyclization reaction is used to prepare the acridine compound represented by a formula I, wherein various groups are defined in the specification; and the method has advantages of mild reaction condition, simple operation and wide substrate applicability, and the multi-functional group acridine compound and the derivative thereof can be prepared in the high yield manner. The formula I is defined in the specification.
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Paragraph 0145; 0146; 0148; 0149
(2017/02/17)
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- O-Naphthoquinone-Catalyzed Aerobic Oxidation of Amines to (Ket)imines: A Modular Catalyst Approach
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A modular aerobic oxidation of amines to imines has been achieved using an ortho-naphthoquinone (o-NQ) catalyst. The cooperative catalyst system of o-NQ and Cu(OAc)2 enabled the formation of homocoupled imines from benzylamines, while the presence of TFA helped the formation of cross-coupled imines in excellent yields. The current mild aerobic oxidation protocol could also be applied to the oxidation of secondary amines to imines or ketimines with the help of cocatalyst, Ag2CO3, with excellent yields.
- Goriya, Yogesh,Kim, Hun Young,Oh, Kyungsoo
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supporting information
p. 5174 - 5177
(2016/10/14)
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- Cu-Catalyzed Aerobic Oxidation of Di-tert-butyl Hydrazodicarboxylate to Di-tert-butyl Azodicarboxylate and Its Application on Dehydrogenation of 1,2,3,4-Tetrahydroquinolines under Mild Conditions
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A new class of co-catalytic system was developed with homogeneous CuI and di-tert-butyl azodicarboxylate for aerobic dehydrogenation of 1,2,3,4-tetrahydroquinolines under mild conditions. The developed co-catalytic system is consisting of di-tert-butyl azodicarboxylate-mediated dehydrogenation of 1,2,3,4-tetrahydroquinoline and aerobic oxidative regeneration of di-tert-butyl azodicarboxylate from di-tert-butyl hydrazodicarboxylate using molecular oxygen as a terminal oxidant. A variety of quinolines were efficiently synthesized by the developed Cu and di-tert-butyl azodicarboxylate co-catalytic system.
- Jung, Dahyeon,Kim, Min Hye,Kim, Jinho
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supporting information
p. 6300 - 6303
(2016/12/23)
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- Tandem arylation/friedel-crafts reactions of o-acylanilines with diaryliodonium salts: A modular synthesis of acridine derivatives
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A modular method to synthesize acridine derivatives was developed with o-acylanilines and diaryliodonium salts. The reactions proceeded smoothly under Cu-catalyzed or metal-free reaction conditions at elevated temperature through tandem arylation/Friedel-Crafts reactions.
- Pang, Xinlong,Lou, Zhenbang,Li, Ming,Wen, Lirong,Chen, Chao
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p. 3361 - 3369
(2015/05/20)
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- Cooperative dehydrogenation of N-heterocycles using a carbon nanotube-rhodium nanohybrid
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Rhodium nanoparticles were anchored on carbon nanotubes and the resulting nanohybrid was studied as co-catalyst, along with tert-butylcatechol, for the dehydrogenation of various N-heterocycles. The co-catalytic system operates in high yields, under the mildest conditions reported so far, and can be applied to a wide variety of secondary amine-containing scaffolds.
- Jawale, Dhanaji V.,Gravel, Edmond,Shah, Nimesh,Dauvois, Vincent,Li, Haiyan,Namboothiri, Irishi N.N.,Doris, Eric
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supporting information
p. 7039 - 7042
(2015/05/05)
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- Synthesis and Characterization of Iron-Nitrogen-Doped Graphene/Core-Shell Catalysts: Efficient Oxidative Dehydrogenation of N-Heterocycles
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An important goal for nanocatalysis is the development of flexible and efficient methods for preparing active and stable core-shell catalysts. In this respect, we present the synthesis and characterization of iron oxides surrounded by nitrogen-doped-graphene shells immobilized on carbon support (labeled FeOx@NGr-C). Active catalytic materials are obtained in a simple, scalable and two-step method via pyrolysis of iron acetate and phenanthroline and subsequent selective leaching. The optimized FeOx@NGr-C catalyst showed high activity in oxidative dehydrogenations of several N-heterocycles. The utility of this benign methodology is demonstrated by the synthesis of pharmaceutically relevant quinolines. In addition, mechanistic studies prove that the reaction progresses via superoxide radical anions (·O2-).
- Cui, Xinjiang,Li, Yuehui,Bachmann, Stephan,Scalone, Michelangelo,Surkus, Annette-Enrica,Junge, Kathrin,Topf, Christoph,Beller, Matthias
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supporting information
p. 10652 - 10658
(2015/09/28)
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- Organocatalytic Aerobic Oxidation of Benzylic sp3 C-H Bonds of Ethers and Alkylarenes Promoted by a Recyclable TEMPO Catalyst
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An entirely metal-free catalyst system consisting of an easily prepared recyclable new TEMPO derived sulfonic salt catalyst, and mineral acids (NaNO2 and HCl) has been developed for selective aerobic oxidation of structurally diverse benzylic sp3 C-H bonds of ethers and alkylarenes. The mild reaction conditions allow for the generation of synthetically and biologically valued isochromanones and xanthones from readily accessible alkyl aromatic precursors in good yields.
- Zhang, Zhiguang,Gao, Yuan,Liu, Yuan,Li, Jianjun,Xie, Hexin,Li, Hao,Wang, Wei
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supporting information
p. 5492 - 5495
(2015/11/18)
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- Online Investigation of Aqueous-Phase Electrochemical Reactions by Desorption Electrospray Ionization Mass Spectrometry
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Electrochemistry (EC) combined with mass spectrometry (MS) is a powerful tool for elucidation of electrochemical reaction mechanisms. However, direct online analysis of electrochemical reaction in aqueous phase was rarely explored. This paper presents the online investigation of several electrochemical reactions with biological relevance in the aqueous phase, such as nitrosothiol reduction, carbohydrate oxidation, and carbamazepine oxidation using desorption electrospray ionization mass spectrometry (DESI-MS). It was found that electroreduction of nitrosothiols [e.g.; nitrosylated insulin B (13-23)] leads to free thiols by loss of NO, as confirmed by online MS analysis for the first time. The characteristic mass shift of 29 Da and the reduced intensity provide a quick way to identify nitrosylated species. Equally importantly, upon collision-induced dissociation (CID), the reduced peptide ion produces more fragment ions than its nitrosylated precursor ion (presumably the backbone fragmentation cannot compete with the facile NO loss for the precursor ion), thus facilitating peptide sequencing. In the case of saccharide oxidation, it was found that glucose undergoes electro-oxidation to produce gluconic acid at alkaline pH, but not at neutral and acidic pHs. Such a pH-dependent electrochemical behavior was also observed for disaccharides such as maltose and cellobiose. Upon electrochemical oxidation, carbamazepine was found to undergo ring contraction and amide bond cleavage, which parallels the oxidative metabolism observed for this drug in leucocytes. The mechanistic information of these redox reactions revealed by EC/DESI-MS would be of value in nitroso-proteome research and carbohydrate/drug metabolic studies.
- Lu, Mei,Liu, Yong,Helmy, Roy,Martin, Gary E.,Dewald, Howard D.,Chen, Hao
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p. 1676 - 1685
(2015/09/22)
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- Facile synthesis of acridines via Pd(0)-diphosphine complex-catalyzed tandem coupling/cyclization protocol
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A facile and efficient approach for the synthesis of a variety of acridines via the tandem coupling/cyclization of substituted 2-bromobenzaldehydes and anilines is described. The reaction can be accomplished with ease in the presence of a catalytic amount of Pd2(dba)3 and diphosphine ligand dppf, providing a broad range of substituted acridines in good to excellent yields (up to 99%). The Lewis acid, AlCl3, is required to promote the cyclization for less electron-rich anilines.
- Wang, Ting-Jun,Chen, Wen-Wen,Li, Yi,Xu, Ming-Hua
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p. 6580 - 6586
(2015/06/16)
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- PhI(OAc)2-mediated intramolecular oxidative aryl-aldehyde C sp 2-C sp 2 bond formation: Metal-free synthesis of acridone derivatives
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A metal-free protocol for direct aryl-aldehyde Csp2-Csp 2 bond formation via a PhI(OAc)2-mediated intramolecular cross-dehydrogenative coupling (CDC) of various 2-(N-arylamino)aldehydes was developed. The novel methodology requires no need of preactivation of the aldehyde group, is applicable to a large variety of functionalized substrates, and most of all provides a convenient approach to the construction of biologically important acridone derivatives.
- Zheng, Zisheng,Dian, Longyang,Yuan, Yucheng,Zhang-Negrerie, Daisy,Du, Yunfei,Zhao, Kang
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p. 7451 - 7458
(2014/09/17)
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