- Triple helicate constructed by covalent bondings: Crystal structure and effective synthesis based on propeller-like substructures
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(Chemical Equation Presented) A triple helicate, having a macrocyclic aromatic amide structure, was synthesized in high yield because of a preorganized component of the tertiary benzenetrianilide moieties in a propeller-like syn conformation at both ends. The helicity was derived from tilted T-shaped aromatic-aromatic (CH-π) interactions between each of the N-phenyl rings.
- Tominaga, Masahide,Masu, Hyuma,Katagiri, Kosuke,Kato, Takako,Azumaya, Isao
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- Highly Active Ni Nanoparticles on N-doped Mesoporous Carbon with Tunable Selectivity for the One-Pot Transfer Hydroalkylation of Nitroarenes with EtOH in the Absence of H2
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Cost-effective and environmentally friendly conversion of nitroarenes into value-added products is desirable but still challenging. In this work, highly dispersed Ni nanoparticles (NPs) supported on N-doped mesoporous carbon (Ni/NC-x) were synthesized via novel ion exchange-pyrolysis strategy. Their catalytic performance was investigated for one-pot transfer hydroalkylation of nitrobenzene (NB) with EtOH in absence of H2. Interestingly, the catalytic performance could be easily manipulated by tuning the morphology and electronic state of Ni NPs via varying the pyrolysis temperature. It was found that the Ni/NC-650 achieved 100 % nitrobenzene conversion and approx. 90 % selectivity of N,N-diethyl aniline at 240 °C for 5 h, more active than those of homogeneous catalysts or supported Ni catalysts prepared by impregnation (Ni/NC-650-IM, Ni/SiO2). This can be ascribed to the higher dispersion and better reducibility as well as richer surface basicity of the catalyst. More interestingly, the Ni/NC-650 catalyst achieved complete conversion of various nitroarenes, yielding imines, secondary amines, or tertiary amines selectively by simply controlling the reaction temperature at 180, 200 and 240 °C, respectively. The one-pot hydrogen-free process with non-noble metal catalysts, as demonstrated in this work, shows great promise for selective conversion of nitroarenes with ethanol to various anilines at industrial scale, from an economic, environmental, and safety viewpoint.
- Tao, Yuewen,Nie, Yunqing,Hu, Haitao,Wang, Ke,Chen, Yi,Nie, Renfeng,Wang, Jianshe,Lu, Tianliang,Zhang, Yongsheng,Xu, Chunbao Charles
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p. 4243 - 4250
(2021/08/20)
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- Mild catalytic deoxygenation of amides promoted by thorium metallocene
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The organoactinide-catalyzed (Cp*2ThMe2) hydroborated reduction of a wide range of tertiary, secondary, and primary amides to the corresponding amines/amine-borane adductsviadeoxygenation of the amides is reported herein. The catalytic reactions proceed under mild conditions with low catalyst loading and pinacolborane (HBpin) concentration in a selective fashion. Cp*2ThMe2is capable of efficiently catalysing the gram-scale reaction without a drop in efficiency. The amine-borane adducts are successfully converted into free amine products in high conversions, which increases the usefulness of this catalytic system. A plausible mechanism is proposed based on detailed kinetics, stoichiometric, and deuterium labeling studies.
- Eisen, Moris S.,Saha, Sayantani
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supporting information
p. 12835 - 12841
(2020/10/05)
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- Direct N-Alkylation/Fluoroalkylation of Amines Using Carboxylic Acids via Transition-Metal-Free Catalysis
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A scalable protocol of direct N-mono/di-alkyl/fluoroalkylation of primary/secondary amines has been constructed with various carboxylic acids as coupling agents under the catalysis of a simple air-tolerant inorganic salt, K3PO4. Advantageous features include 100 examples, 10 drugs and drug-like amines, fluorinated complex tertiary amines, gram-scale synthesis and isotope-labelling amine, thus demonstrating the potential applicability in industry of this methodology. The involvement of relatively less reactive silicon-hydride compared with the traditional reactive metal-hydride or boron-hydride species required to reduce the amide intermediates presumably contributes to the remarkable functional group compatibility. (Figure presented.).
- Lu, Chunlei,Qiu, Zetian,Xuan, Maojie,Huang, Yan,Lou, Yongjia,Zhu, Yiling,Shen, Hao,Lin, Bo-Lin
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supporting information
p. 4151 - 4158
(2020/08/21)
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- Continuous-Flow Amide and Ester Reductions Using Neat Borane Dimethylsulfide Complex
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Reductions of amides and esters are of critical importance in synthetic chemistry, and there are numerous protocols for executing these transformations employing traditional batch conditions. Notably, strategies based on flow chemistry, especially for amide reductions, are much less explored. Herein, a simple process was developed in which neat borane dimethylsulfide complex (BH3?DMS) was used to reduce various esters and amides under continuous-flow conditions. Taking advantage of the solvent-free nature of the commercially available borane reagent, high substrate concentrations were realized, allowing outstanding productivity and a significant reduction in E-factors. In addition, with carefully optimized short residence times, the corresponding alcohols and amines were obtained in high selectivity and high yields. The synthetic utility of the inexpensive and easily implemented flow protocol was further corroborated by multigram-scale syntheses of pharmaceutically relevant products. Owing to its beneficial features, including low solvent and reducing agent consumption, high selectivity, simplicity, and inherent scalability, the present process demonstrates fewer environmental concerns than most typical batch reductions using metal hydrides as reducing agents.
- ?tv?s, Sándor B.,Kappe, C. Oliver
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p. 1800 - 1807
(2020/02/27)
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- Alkylation of Aromatic Amines with Trialkyl Amines Catalyzed by a Defined Iridium Complex with a 2-Hydroxypyridylmethylene Fragment
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Six Cp?Ir complexes containing NN-bitentate chelate ligands [Cp?IrCl(C5H4CH2C5H3OH)][Cl] (1), [Cp?IrCl(C5H4CH2C5H3O)] (2), [Cp?IrCl(C5H4C5H3OH)] [Cl] (3), [Cp?IrCl(C5H4CH2C5H4)][Cl] (4), [Cp?IrCl(CH3OC5H3CH2C5H3OCH3)][Cl] (5), and [Cp?IrCl(CH3OC5H3CH2C5H3OH)][Cl] (6) were synthesized and characterized. Complex 1 could be transformed to 2 when reacted with NaOtBu or NEt3 via -OH deprotonation. These six complexes were tested as catalysts for mono-N-alkylation of amines with trialkyl amines, and complex 1 exhibited highest activity. The coupling reactions proceed under air condition, with 1 mol % catalyst loading without extra base in methanol at 120 °C and can be further accelerated by adding NR3·HCl.
- Deng, Danfeng,Hu, Bowen,Zhang, Ziyu,Mo, Shengkai,Yang, Min,Chen, Dafa
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p. 2218 - 2226
(2019/05/21)
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- B(C6F5)3-Catalyzed Deoxygenative Reduction of Amides to Amines with Ammonia Borane
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The first B(C6F5)3-catalyzed deoxygenative reduction of amides into the corresponding amines with readily accessible and stable ammonia borane (AB) as a reducing agent under mild reaction conditions is reported. This metal-free protocol provides facile access to a wide range of structurally diverse amine products in good to excellent yields, and various functional groups including those that are reduction-sensitive were well tolerated. This new method is also applicable to chiral amide substrates without erosion of the enantiomeric purity. The role of BF3 ? OEt2 co-catalyst in this reaction is to activate the amide carbonyl group via the in situ formation of an amide-boron adduct. (Figure presented.).
- Pan, Yixiao,Luo, Zhenli,Han, Jiahong,Xu, Xin,Chen, Changjun,Zhao, Haoqiang,Xu, Lijin,Fan, Qinghua,Xiao, Jianliang
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supporting information
p. 2301 - 2308
(2019/01/30)
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- Ru-Catalyzed Deoxygenative Transfer Hydrogenation of Amides to Amines with Formic Acid/Triethylamine
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A ruthenium(II)-catalyzed deoxygenative transfer hydrogenation of amides to amines using HCO2H/NEt3 as the reducing agent is reported for the first time. The catalyst system consisting of [Ru(2-methylallyl)2(COD)], 1,1,1-tris(diphenylphosphinomethyl) ethane (triphos) and Bis(trifluoromethane sulfonimide) (HNTf2) performed well for deoxygenative reduction of various secondary and tertiary amides into the corresponding amines in high yields with excellent selectivities, and exhibits high tolerance toward functional groups including those that are reduction-sensitive. The choice of hydrogen source and acid co-catalyst is critical for catalysis. Mechanistic studies suggest that the reductive amination of the in situ generated alcohol and amine via borrowing hydrogen is the dominant pathway. (Figure presented.).
- Pan, Yixiao,Luo, Zhenli,Xu, Xin,Zhao, Haoqiang,Han, Jiahong,Xu, Lijin,Fan, Qinghua,Xiao, Jianliang
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supporting information
p. 3800 - 3806
(2019/07/12)
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- Boron Lewis Acid Promoted Ruthenium-Catalyzed Hydrogenation of Amides: An Efficient Approach to Secondary Amines
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The hydrogenation of amides to amines has been developed by using the catalyst [Ru(H)2(CO)(Triphos)] (Triphos=1,1,1-tri(diphenylphosphinomethyl)ethane) and catalytic boron Lewis acids such as B(C6F5)3 or BF3?Et2O as additives. The reaction provides an efficient method for the preparation of secondary amines from amides in good yields with high selectivity.
- Yuan, Ming-Lei,Xie, Jian-Hua,Zhou, Qi-Lin
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p. 3036 - 3040
(2016/10/11)
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- Chelating Bis(1,2,3-triazol-5-ylidene) Rhodium Complexes: Versatile Catalysts for Hydrosilylation Reactions
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NHC-rhodium complexes (NHC=N-heterocyclic carbenes) have been widely used as efficient catalysts for hydrosilylation reactions. However, the substrates were mostly limited to reactive carbonyl compounds (aldehydes and ketones) or carbon-carbon multiple bonds. Here, we describe the application of newly-developed chelating bis(tzNHC)-rhodium complexes (tz=1,2,3-triazol-5-ylidene) for several reductive transformations. With these catalysts, the formal reductive methylation of amines using carbon dioxide, the hydrosilylation of amides and carboxylic acids, and the reductive alkylation of amines using carboxylic acids have been achieved under mild reaction conditions.
- Nguyen, Thanh V. Q.,Yoo, Woo-Jin,Kobayashi, Shu
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supporting information
p. 452 - 458
(2016/02/12)
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- Deoxygenative Hydrogenation of Amides Catalyzed by a Well-Defined Iridium Pincer Complex
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The iridium-catalyzed highly chemoselective hydrogenation of amides to amines has been developed. Using a well-defined iridium catalyst bearing a P(O)C(O)P pincer ligand combined with B(C6F5)3, the C-O cleavage products are formed under mild reaction conditions. The reaction provides a new method for the preparation of amines from amides in good yield with high selectivity.
- Yuan, Ming-Lei,Xie, Jian-Hua,Zhu, Shou-Fei,Zhou, Qi-Lin
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p. 3665 - 3669
(2016/07/06)
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- Design, synthesis, and biological evaluation of 1,2,4-triazole bearing 5-substituted biphenyl-2-sulfonamide derivatives as potential antihypertensive candidates
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A series of novel 1,2,4-triazole bearing 5-substituted biphenyl-2- sulfonamide derivatives were designed and synthesized to develop new angiotensin II subtype 2 (AT2) receptor agonists as novel antihypertensive candidates. It was found that 14f (IC50 = 0.4 nM) and 15e (IC 50 = 5.0 nM) displayed potent AT2 receptor affinity and selectivity in binding assays. Biological evaluation in vivo suggested that 14f is obviously superior to that of reference drug losartan in RHRs, and meanwhile, 14f has no significant impact on heart rate. The interesting activities of these compounds may make them promising candidates as antihypertensive agents.
- Liu, Jie,Liu, Qin,Yang, Xue,Xu, Shengtao,Zhang, Hengyuan,Bai, Renren,Yao, Hequan,Jiang, Jieyun,Shen, Mingqin,Wu, Xiaoming,Xu, Jinyi
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p. 7742 - 7751
(2014/01/06)
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- Aerobic oxidative N-dealkylation of tertiary amines in aqueous solution catalyzed by rhodium porphyrins
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Aerobic oxidative N-dealkylation of a variety of aliphatic tertiary amines and anilines catalyzed by rhodium(iii) tetra (p-sulfonatophenyl) porphyrin ((TSPP)RhIII) is achieved in aqueous solution using dioxygen as the sole oxidant.
- Ling, Zhen,Yun, Lin,Liu, Lianghui,Wu, Bing,Fu, Xuefeng
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supporting information
p. 4214 - 4216
(2013/05/22)
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- Potent direct inhibitors of factor Xa based on the tetrahydroisoquinoline scaffold
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Direct inhibition of coagulation factor Xa (FXa) carries significant promise for developing effective and safe anticoagulants. Although a large number of FXa inhibitors have been studied, each can be classified as either possessing a highly flexible or a rigid core scaffold. We reasoned that an intermediate level of flexibility will provide high selectivity for FXa considering that its active site is less constrained in comparison to thrombin and more constrained as compared to trypsin. We studied several core scaffolds including 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid for direct FXa inhibition. Using a genetic algorithm-based docking and scoring approach, a promising candidate 23 was identified, synthesized, and found to inhibit FXa with a Ki of 28 μM. Optimization of derivative 23 resulted in the design of a potent dicarboxamide 47, which displayed a Ki of 135 nM. Dicarboxamide 47 displayed at least 1852-fold selectivity for FXa inhibition over other coagulation enzymes and doubled PT and aPTT of human plasma at 17.1 μM and 20.2 μM, respectively, which are comparable to those of clinically relevant agents. Dicarboxamide 47 is expected to serve as an excellent lead for further anticoagulant discovery.
- Al-Horani, Rami A.,Mehta, Akul Y.,Desai, Umesh R.
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p. 771 - 783
(2012/09/08)
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- A Lewis acid mediated schmidt reaction of benzylic azide: Synthesis of sterically crowded aromatic tertiary amines
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An efficient one-pot synthesis of sterically hindered aromatic tertiary amines through Lewis acid induced intermolecular Schmidt reaction of benzylic azides is described. In the presence of EtAlCl2, benzylic azide underwent a smooth Schmidt reaction to give the corresponding iminium ion, which, upon reduction with NaBH4 in situ, afforded the tertiary amine. The effects of substituents on the aromatic ring and the steric effects of the alkyl side chain have also been studied.
- Murali, Annamalai,Puppala, Manohar,Varghese, Babu,Baskaran, Sundarababu
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supporting information; experimental part
p. 5297 - 5302
(2011/11/12)
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- Assembly of substituted 2-alkylquinolines by a sequential palladium-catalyzed Ci-N and Ci-C bond formation
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Diversity: A range of substituted 2-alkylquinolines can be prepared in a general and efficient synthetic approach that employs mild reaction conditions (see scheme). The synthesis is based on a sequential palladium-catalyzed Ci-N and Ci-C bond formation, followed by palladium-catalyzed aromatization, and results in the formation of the desired compounds in one step. Copyright
- Matsubara, Yoshio,Hirakawa, Saori,Yamaguchi, Yoshihiro,Yoshida, Zen-Ichi
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experimental part
p. 7670 - 7673
(2011/10/05)
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- BENZENE OR THIOPHENE DERIVATIVE AND USE THEREOF AS VAP-1 INHIBITOR
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The present invention provides a novel benzene derivative or thiophene derivative useful as a VAP-1 inhibitor, or a medicament for the prophylaxis or treatment of a VAP-1 associated disease and the like, namely, a compound represented by the formula (I): wherein each symbol is as defined in the present specification, or a pharmaceutically acceptable salt thereof.
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Page/Page column 100
(2009/12/27)
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- Anilide derivative, production and use thereof
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This invention is to provide a compound of the formula: wherein R1is an optionally substituted 5- to 6-membered ring; the ring A is an optionally substituted 6- to 7-membered ring; the ring B is an optionally substituted benzene ring; n is an integer of 1 or 2; Z is a chemical bond or a divalent group; R2is (1) an optionally substituted amino group in which a nitrogen atom may form a quaternary ammonium, (2) an optionally substituted nitrogen-containing heterocyclic ring group which may contain a sulfur atom or an oxygen atom as ring constituting atoms and wherein a nitrogen atom may form a quaternary ammonium, (3) a group binding through a sulfur atom or (4) a group of the formula: ?wherein k is 0 or 1, and when k is 0, a phosphorus atom may form a phosphonium; and R5and R6are independently an optionally substituted hydrocarbon group, an optionally substituted hydroxy group or an optionally substituted amino group, and R5and R6may bind to each other to form a cyclic group together with the adjacent phosphorus atom, or a salt thereof , which is useful for antagonizing CCR5 and also for the prevention and treatment of infectious disease of HIV.
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- Compounds, polymers, resin compositions and nonlinear optical devices
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The present invention provides, as heteroaromatic compounds made functional so as to be used for nonlinear optical materials, compounds represented by the following general formula (1), and also provides polymers obtained from these and nonlinear optical parts comprising such polymers. In the formula, Ar1 and Ar2 each represents a divalent aromatic group; R1, R2 and R3 each represents an atom or a group independently selected from a hydrogen atom or an alkyl group and an aromatic group; X1 represents a monovalent organic group; n represents an integer of 2 to 12; and Z1 and Z2 each represents a group independently selected from electron attractive functional groups.
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- Zirconium borohydride - A versatile reducing agent for the reduction of electrophilic and nucleophilic substrates
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Zirconium borohydride, a potential reducing agent, reduces acids, esters, imines to the corresponding alcohols and secondary amines in good yield at room temperature within two hours. This facile reducing property was taken advantage off in the synthesis of pheromones and some novel chiral precursors for asymmetric synthesis.
- Narasimhan,Balakumar
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p. 4387 - 4395
(2007/10/03)
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- Unusual reactivity of zinc borohydride - Reduction of amides to amines
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Zinc borohydride reduces secondary amides to the corresponding N-ethyl amines in excellent yields. The reduction requires only stoichiometric quantities of hydride and does not require the addition of any Lewis acid. The amides are isolated by simple hydrolysis of the reaction mixture.
- Narasimhan,Madhavan,Balakumar,Swarnalakshmi
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p. 391 - 394
(2007/10/03)
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- Alkylation of aromatic amines and related compounds using a copper(II)-aluminum(III) couple
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Copper(II)-mediated alkylation of amines and related compounds (e.g. hydrazines, hydrazones, hydroxylamines) using an alkyl aluminum reagent is described. The reaction proceeds selectively and in good yield, utilizing a metal-metal exchange as the key step.
- Barton, Derek H.R.,Doris, Eric
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p. 3295 - 3298
(2007/10/03)
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