- SYNTHESES AND REACTIONS OF DIAMINOOXOSULFONIUM SALTS
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Diaminooxosulfonium salts were prepared by alkylation of aminosulfoximines.Their reactions with dimsyl sodium gave the corresponding ylides and sulfoximines.The intramolecular rearrangement of the ylide led to ortho substitution via an intermediate cyclohexadienoneimine.Hydrogen transfer, accompaning rearomatization and the subsequent action of a base gave a dihydrobenzoisothiazole derivative.
- Okuma, Kentaro,Higuchi, Naotsugu,Otha, Hiroshi,Kobayashi, Michio
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- Novel hybrid conjugates with dual estrogen receptor α degradation and histone deacetylase inhibitory activities for breast cancer therapy
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Hormone therapy targeting estrogen receptors is widely used clinically for the treatment of breast cancer, such as tamoxifen, but most of them are partial agonists, which can cause serious side effects after long-term use. The use of selective estrogen receptor down-regulators (SERDs) may be an effective alternative to breast cancer therapy by directly degrading ERα protein to shut down ERα signaling. However, the solely clinically used SERD fulvestrant, is low orally bioavailable and requires intravenous injection, which severely limits its clinical application. On the other hand, double- or multi-target conjugates, which are able to synergize antitumor activity by different pathways, thus may enhance therapeutic effect in comparison with single targeted therapy. In this study, we designed and synthesized a series of novel dual-functional conjugates targeting both ERα degradation and histone deacetylase inhibiton by combining a privileged SERD skeleton 7-oxabicyclo[2.2.1]heptane sulfonamide (OBHSA) with a histone deacetylase inhibitor side chain. We found that substituents on both the sulfonamide nitrogen and phenyl group of OBHSA unit had significant effect on biological activities. Among them, conjugate 16i with N-methyl and naphthyl groups exhibited potent antiproliferative activity against MCF-7 cells, and excellent ERα degradation activity and HDACs inhibitory ability. A further molecular docking study indicated the interaction patterns of these conjugates with ERα, which may provide guidance to design novel SERDs or PROTAC-like SERDs for breast cancer therapy.
- Zhao, Chenxi,Tang, Chu,Li, Changhao,Ning, Wentao,Hu, Zhiye,Xin, Lilan,Zhou, Hai-Bing,Huang, Jian
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- Hydrosilylative reduction of primary amides to primary amines catalyzed by a terminal [Ni-OH] complex
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A terminal [Ni-OH] complex1, supported by triflamide-functionalized NHC ligands, catalyzes the hydrosilylative reduction of a range of primary amides into primary amines in good to excellent yields under base-free conditions with key functional group tolerance. Catalyst1is also effective for the reduction of a variety of tertiary and secondary amides. In contrast to literature reports, the reactivity of1towards amide reduction follows an inverse trend,i.e., 1° amide > 3° amide > 2° amide. The reaction does not follow a usual dehydration pathway.
- Bera, Jitendra K.,Pandey, Pragati
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p. 9204 - 9207
(2021/09/20)
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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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- Photocatalytic Water-Splitting Coupled with Alkanol Oxidation for Selective N-alkylation Reactions over Carbon Nitride
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Photocatalytic water splitting technology (PWST) enables the direct use of water as appealing “liquid hydrogen source” for transfer hydrogenation reactions. Currently, the development of PWST-based transfer hydrogenations is still in an embryonic stage. Previous reports generally centered on the rational utilization of the in situ generated H-source (electrons) for hydrogenations, in which photogenerated holes were quenched by sacrificial reagents. Herein, the fully-utilization of the liquid H-source and holes during water splitting is presented for photo-reductive N-alkylation of nitro-aromatic compounds. In this integrate system, H-species in situ generated from water splitting were designed for nitroarenes reduction to produce amines, while alkanols were oxidized by holes for cascade alkylating of anilines as well as the generated secondary amines. More than 50 examples achieved with a broad range scope validate the universal applicability of this mild and sustainable coupling approach. The synthetic utility of this protocol was further demonstrated by the synthesis of existing pharmaceuticals via selective N-alkylation of amines. This strategy based on the sustainable water splitting technology highlights a significant and promising route for selective synthesis of valuable N-alkylated fine chemicals and pharmaceuticals from nitroarenes and amines with water and alkanols.
- Xu, Yangsen,Zhang, Zhaofei,Qiu, Chuntian,Chen, Shaoqin,Ling, Xiang,Su, Chenliang
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p. 582 - 589
(2020/12/09)
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- A highly efficient Co-based catalyst fabricated by coordination-assisted impregnation strategy towards tandem catalytic functionalization of nitroarenes with various alcohols
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A well-defined hexamethylenetetramine (abbreviated as HMTA) based two-dimensional (2D) MOFs metalloligand (termed Zn-HMTA), with free uncoordinated tertiary amine groups, has been synthesized via solution diffusion method for the first time. The crystal structure of 2D Zn-HMTA metalloligand was determined by the single crystal X-ray diffraction (SCXRD). The SCXRD and X-ray photoelectron spectroscopy (XPS) analyses have revealed that the 2D Zn-HMTA metalloligand is rich in- free tertiary amine groups, which are of strong coordination ability to transition metal ions (e.g. Ni2+, Co2+, Zn2+, Cu2+). As a result, a 2D bimetallic Co@Zn-HMTA MOFs was synthesized via coordination-assisted impregnation (CAI) strategy attributed to the unique feature of strong coordinated ability of free tertiary amine groups. Furthermore, a series of self-supported Co-ZnO-CN nanocatalysts were afforded upon the as-synthesized Co@Zn-HMTA MOFs served as a self-sacrificial template for pyrolysis at different temperatures. The optimized catalyst (termed as Co-ZnO@CN-CAI) demonstrated the excellent catalytic performance for hydrogenation-alkylation tandem reaction in comparison with the classic ZnO@CN composite (derived from Zn-HMTA MOFs) supported metallic Co catalyst (Co-ZnO@CN-IWI) prepared by incipient wetness impregnation method. Moreover, the kinetic study was also performed to confirm that the alkylation is the rate-determining step in the hydrogenation-alkylation tandem reaction. The origin of enhanced catalytic performance of Co-ZnO@CN-CAI and the role of Co@Zn-HMTA MOFs precursor have been explored by way of various characterizations, e.g. HADDF-STEM-EDS, SEM-EDS, 13C MAS NMR, XRD, Raman and XPS, etc. It is anticipated that the prepared low-cost and easily prepared 2D Zn-HMTA metalloligand will become a general template for synthesis of highly self-supported catalysts with coordination-assisted impregnation strategy (CAI) for various catalytic reactions.
- Li, Guangming,Li, Jingfang,Li, Weizuo,Li, Xuewei,Li, Zhibin,Mao, Guijie,She, Wei,Wang, Jing
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p. 462 - 474
(2021/11/11)
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- Selective Pd-catalyzed monoarylation of small primary alkyl amines through backbone-modification in ylide-functionalized phosphines (YPhos)
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Ylide-substituted phosphines have been shown to be excellent ligands for C-N coupling reactions under mild reaction conditions. Here we report studies on the impact of the steric demand of the substituent in the ylide-backbone on the catalytic activity. Two new YPhos ligands with bulky ortho-tolyl (pinkYPhos) and mesityl (mesYPhos) substituents were synthesized, which are slightly more sterically demanding than their phenyl analogue but considerably less flexible. This change in the ligand design leads to higher selectivities and yields in the arylation of small primary amines compared to previously reported YPhos ligands. Even MeNH2 and EtNH2 could be coupled at room temperature with a series of aryl chlorides in high yields.
- Rodstein, Ilja,Prendes, Daniel Sowa,Wickert, Leon,Paa?en, Maurice,Gessner, Viktoria H.
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p. 14674 - 14683
(2020/12/29)
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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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- Homogeneous cobalt-catalyzed deoxygenative hydrogenation of amides to amines
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The first general and efficient cobalt-catalyzed deoxygenative hydrogenation of amides to amines is presented. The optimal catalytic system based on a combination of [Co(NTf2)2] and (p-anisyl)triphos (L3) in the presence of [Me3SiOTf] as acidic co-catalyst facilitates the direct hydrogenation of a broad range of amides to the corresponding amines under mild conditions. A set of control experiments indicate that, after the initial reduction of the amide carboxylic group to the well-known hemiaminal intermediate, the reaction mainly proceeds through C-O bond cleavage though other pathways might be also involved to a minor extent. This journal is
- Papa, Veronica,Cabrero-Antonino, Jose R.,Spannenberg, Anke,Junge, Kathrin,Beller, Matthias
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p. 6116 - 6128
(2020/11/03)
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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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- Hydrogenation and: N-Alkylation of anilines and imines via transfer hydrogenation with homogeneous nickel compounds
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The nickel-catalyzed N-Alkylation of a variety of arylamines via transfer hydrogenation in the absence of pressurized hydrogen and basic or acidic additives was achieved in a tandem reaction. This process was further extended to the CN bond reduction and N-Alkylation of a variety of imines with ethanol, the latter acting as a hydrogen and acetaldehyde source, which allowed for the reduction and subsequent condensation to yield the corresponding N-Alkylated products.
- Benitez-Medina, G. Eliad,García, Juventino J.
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supporting information
p. 17579 - 17587
(2019/12/23)
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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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- Cobalt-Catalyzed Reductive Alkylation of Amines with Carboxylic Acids
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Direct reductive alkylation of amines with carboxylic acid is carried out by using an inexpensive, air-stable cobalt/triphos catalytic system with molecular hydrogen as the reductant. This efficient synthetic method proceeds through reduction and condensation, followed by reduction of the in situ-generated imine into the amine in a green catalytic process.
- Emayavaramban, Balakumar,Chakraborty, Priyanka,Sundararaju, Basker
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p. 3089 - 3093
(2018/12/11)
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- A strategy of two-step tandem catalysis towards direct N-alkylation of nitroarenes with ethanol via facile fabricated novel Co-based catalysts derived from coordination polymers
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Three novel N-doped carbon supported Co/Co3O4 catalysts, namely, Co@CN-hmta, Co@CN-larg and Co-Co3O4@CN-bipy, with sheet-, worm-, honeycomb-like morphologies respectively, have been fabricated by the pyrolysis of well-defined coordination polymers (CPs). Upon the as-prepared catalysts were applied for the reaction of N-alkylation of nitroarenes with ethanol, a direct two-step tandem reaction is realized, in which the Co@CN-hmta delivers 100% conversion/selectivity of N-ethylaniline/N,N-diethylaniline from the direct N-alkylation of nitroarenes with ethanol. The kinetic studies were conducted to confirm that the N-alkylation of aniline with ethanol is the rate-determining step in the two-step tandem reaction. The SEM/EDX, XRD, Raman, TEM, XPS, and CO2-TPD characterization results have revealed that sizes and dispersion of metallic Co, amount of structural defects and surface Lewis basicity towards three catalysts can be tuned by changing the structures of Co-based CPs designed by different organic linkers, which may also help to understand the preparation of industrial catalysts on a molecular level. The optimized Co@CN-hmta catalyst is easily recycled by using the external magnet for successive reuses without any loss in both activity and selectivity. To the best of our knowledge, this is the first carbon-nitrogen species supported Co/Co3O4 catalysts derived from the CPs, which could effectively catalyzed the N-alkylation of nitroarenes with ethanol to produce the secondary amines and/or tertiary amines. This low-cost, recyclable and easy scale-up N-doped carbon supported catalyst may be of potential application in various heterogeneous catalytic reactions.
- Wang, Jing,Qi, Tianqinji,Li, Zhibin,She, Wei,Li, Xuewei,Li, Jingfang,Yan, Pengfei,Li, Weizuo,Li, Guangming
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p. 106 - 118
(2019/07/19)
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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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- Tailored Cobalt-Catalysts for Reductive Alkylation of Anilines with Carboxylic Acids under Mild Conditions
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The first cobalt-catalyzed hydrogenative N-methylation and alkylation of amines with readily available carboxylic acid feedstocks as alkylating agents and H2 as ideal reductant is described. Combination of tailor-made triphos ligands with cobalt(II) tetrafluoroborate significantly improved the efficiency, thus promoting the reaction under milder conditions. This novel protocol allows for a broad substrate scope with good functional group tolerance, even in the presence of reducible alkenes, esters, and amides.
- Liu, Weiping,Sahoo, Basudev,Spannenberg, Anke,Junge, Kathrin,Beller, Matthias
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supporting information
p. 11673 - 11677
(2018/09/10)
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- A sound shielding through the level three-stage amine instead new method should be secondary amine
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The invention discloses a novel method for preparing secondary amine by a reaction of primary amine and tertiary amine. The method comprises the following steps of 1, adding primary amine and tertiary amine into a reaction container according to a mole ratio of primary amine to tertiary amine of 1: 3, adding [(Bt)2*Ir*P(nBu)3]OTf as a catalyst (wherein Bt represents phenylbenzothiazole) into the reaction container, adding an organic solvent into the reaction container, and carrying out a reaction process at a temperature of 120-160 DEG C for 6-12h, wherein a mole ratio of primary amine, tertiary amine to catalyst is 1: 3: 0.01, and 2, carrying out purification by a silica gel column of 200-300 meshes, pre-leaching the silica gel column by 20-50mL of petroleum ether, carrying out elution on the leacheate at a leacheate flowing rate of 1-2mL/min for 3-6h so that the solvent is removed and the corresponding secondary amine product is obtained. A research result shows that the novel method for producing secondary amine by a reaction of primary amine and tertiary amine has the characteristics of mild conditions, high conversion rate and no pollutant. The method solves the problems of the existing secondary amine synthesis method and improves secondary amine synthesis.
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Paragraph 0027; 0028; 0029
(2017/06/02)
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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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- Alanine triazole iridium-catalyzed C–N bond formation through borrowing hydrogen strategy
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An efficient synthesis of secondary amines has been described through alanine triazole iridium-catalyzed C–N bond formation of an aromatic amine and an alkyl amine using the borrowing hydrogen strategy. In addition, it was observed that alanine triazole iridium is also an efficient catalyst to promote C–N bond formation of an aromatic amine and alcohols with good to excellent yields.
- Yu, Xiaoli,Zhao, Ranran,Wan, Huida,Yang, Yongchun,Wang, Dawei
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supporting information
p. 4588 - 4591
(2016/09/23)
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- Base-oxidant promoted metal-free N-demethylation of arylamines
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A metal-free oxidative N-demethylation of arylamines with triethylamine as a base and tert-butyl hydroperoxide (TBHP) as oxidant is reported in this paper. The reaction is general, practical, inexpensive, non-toxic, and the method followed is environmentally benign, with moderate to good yields. [Figure not available: see fulltext.]
- Botla, Vinayak,Barreddi, Chiranjeevi,Daggupati, Ramana V,Malapaka, Chandrasekharam
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p. 1469 - 1473
(2016/09/19)
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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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- Towards a general ruthenium-catalyzed hydrogenation of secondary and tertiary amides to amines
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A broad range of secondary and tertiary amides has been hydrogenated to the corresponding amines under mild conditions using an in situ catalyst generated by combining [Ru(acac)3], 1,1,1-tris(diphenylphosphinomethyl)ethane (Triphos) and Yb(OTf)3. The presence of the metal triflate allows to mitigate reaction conditions compared to previous reports thus improving yields and selectivities in the desired amines. The excellent isolated yields of two scale-up experiments corroborate the feasibility of the reaction protocol. Control experiments indicate that, after the initial reduction of the amide carbonyl group, the reaction proceeds through the reductive amination of the alcohol with the amine arising from collapse of the intermediate hemiaminal.
- Cabrero-Antonino, Jose R.,Alberico, Elisabetta,Junge, Kathrin,Junge, Henrik,Beller, Matthias
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p. 3432 - 3442
(2016/05/19)
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- Catalytic N-Alkylation of Amines Using Carboxylic Acids and Molecular Hydrogen
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A convenient, practical and green N-alkylation of amines has been accomplished by applying readily available carboxylic acids in the presence of molecular hydrogen. Applying an in situ formed ruthenium/triphos complex and an organic acid as cocatalyst, a broad range of alkylated secondary and tertiary amines are obtained in good to excellent yields. This novel method is also successfully applied for the synthesis of unsymmetrically substituted N-methyl/alkyl anilines through a direct three-component coupling reaction of the corresponding amines, carboxylic acids, and CO2 as a C1 source.
- Sorribes, Iván,Cabrero-Antonino, Jose R.,Vicent, Cristian,Junge, Kathrin,Beller, Matthias
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supporting information
p. 13580 - 13587
(2015/11/10)
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- Phosphino-amine (PN) Ligands for Rapid Catalyst Discovery in Ruthenium-Catalyzed Hydrogen-Borrowing Alkylation of Anilines: A Proof of Principle
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A general synthetic protocol for the synthesis of simple phosphino-amine (PN) ligands is described with 19 ligands being isolated in good yields. High-throughput ligand screening uncovered the success of two of these ligands for aromatic amine alkylations via ruthenium-catalyzed hydrogen borrowing reactions. The combination of N,N'-bis(diphenylphosphino)-N,N′-dimethylpropylenediamine with a ruthenium(II) source and potassium hydroxide (15 mol%) is the optimal system for selective monobenzylations of aromatic amines (method A). Over 70% isolated yields have been achieved for the formation of 14 secondary aromatic amines under mild reaction conditions (120 C and 1.05 equivalents of benzyl alcohol). On the other hand, N,N-bis(diphenylphosphino)-isopropylamine was the ligand utilized for both selective monomethylation and monoethylation reactions of aromatic amines (method B). Here the alcohol is charged as both the reaction medium and substrate and 9 examples are disclosed with all isolated yields exceeding 70%. These methods have been applied to the synthesis of important synthetic building blocks based on aminoferrocene.
- Broomfield, Lewis Marc,Wu, Yichen,Martin, Eddy,Shafir, Alexandr
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supporting information
p. 3538 - 3548
(2016/01/25)
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- Nickel-catalyzed amination of Aryl chlorides with ammonia or ammonium salts
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The nickel-catalyzed amination of aryl chlorides to form primary arylamines occurs with ammonia or ammonium sulfate and a well-defined single-component nickel(0) precatalyst containing a Josiphos ligand and an η2-bound benzonitrile ligand. This system also catalyzes the coupling of aryl chlorides with gaseous amines in the form of their hydrochloride salts. Simple alternative: The title reaction, which results in primary arylamines, is catalyzed by well-defined single-component nickel(0) precatalysts containing a Josiphos ligand and an η2-bound benzonitrile ligand. This system also catalyzes the coupling of aryl chlorides with gaseous amines in the form of their hydrochloride salts.
- Green, Rebecca A.,Hartwig, John F.
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supporting information
p. 3768 - 3772
(2015/03/18)
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- Iridium-CNP complex catalyzed cross-coupling of primary alcohols and secondary alcohols by a borrowing hydrogen strategy
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A highly efficient C-C bond formation has been developed through the cross-coupling of primary and secondary alcohols. The corresponding functionalized ketones were obtained with an iridium-CNP complex as a catalyst through the borrowing hydrogen strategy. The present methodology provides an easy alternative method to aldol reaction derivatives. More importantly, the complexes were also effective catalysts for the alkylation of an aromatic amine with a tertiary alkyl amine. This journal is
- Wang, Dawei,Zhao, Keyan,Yu, Xin,Miao, Hongyan,Ding, Yuqiang
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p. 42924 - 42929
(2015/02/19)
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- Synthesis, structures of benzoxazolyl iridium(III) complexes, and applications on C-C and C-N bond formation reactions under solvent-free conditions: Catalytic activity enhanced by noncoordinating anion without silver effect
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Several new bisbenzoxazolyl iridium(III) complexes have been synthesized and characterized through X-ray crystallography. These complexes exhibit excellent catalytic activity in C-C and C-N bond formation reactions from the alkylation of amine with amine, amine with alcohol, ketone with alcohol, and alcohol with alcohol through a borrowing hydrogen reaction. Moreover, these iridium(III) complexes are effective catalysts for the alkylation of amine with alcohol and ketone with alcohol under solvent-free conditions. The catalytic activity of these complexes is greatly enhanced by noncoordinating, while the experiments have excluded the possibility of a "silver effect" (bimetallic catalysis or silver-assisted metal catalysis) from the experiments.
- Wang, Dawei,Zhao, Keyan,Xu, Chongying,Miao, Hongyan,Ding, Yuqiang
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p. 3910 - 3918
(2014/12/12)
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- Ruthenium-catalyzed N-alkylation of amines with alcohols under mild conditions using the borrowing hydrogen methodology
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Using a simple amino amide ligand, ruthenium-catalyzed one-pot alkylation of primary and secondary amines with simple alcohols was carried out under a wide range of conditions. Using the alcohol as solvent, alkylation was achieved under mild conditions, even as low as room temperature. Reactions occurred with high conversion and selectivity in many cases. Reactions can also be carried out at high temperatures in organic solvent with high selectivity using stoichiometric amounts of the alcohol.
- Enyong, Arrey B.,Moasser, Bahram
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p. 7553 - 7563
(2014/09/17)
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- Direct catalytic N-alkylation of amines with carboxylic acids
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A straightforward process for the N-alkylation of amines has been developed applying readily available carboxylic acids and silanes as the hydride source. Complementary to known reductive aminations, effective C-N bond construction proceeds under mild conditions and allows obtaining a broad range of alkylated secondary and tertiary amines, including fluoroalkyl-substituted anilines as well as the bioactive compound Cinacalcet HCl.
- Sorribes, Iván,Junge, Kathrin,Beller, Matthias
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p. 14314 - 14319
(2014/12/10)
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- 2-[N-Alkyl(R-phenyl)-aminomethyl]-3-phenyl-7-trifluoromethylquinoxalines as anticancer agents inhibitors of folate enzymes
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Based on our previous results on the ascertained potent growth inhibition effect against a panel of 60 human tumors cell lines at National Cancer Institute of Bethesda (NCI), we have synthesized a novel series of thirty-one 2-[N-methyl(R-phenyl)-aminomethyl]-3-phenyl-7-trifluoromethylquinoxalines (1-31). The lead compound 1 was previously reported to be endowed with significant inhibition against hDHFR enzyme, with a Ki of 0.2 μM. Docking studies were performed on compound 1 and here reported to predict its binding conformation to human dihydrofolate reductase (hDHFR). All compounds (1-31) were assayed versus hDHFR and human thymidylate synthase (hTS). From the screening emerged that all compounds inhibited hDHFR with Ki values included between 0.2 and 11 μM, while only a few (6, 21, 24, 27, 29) showed great activity and selectivity towards hTS. Evaluation of the anticancer activity was performed by NCI, first against the three cell line panel, and only the most active compounds (17, 21, 24, 26, 27) were evaluated on a panel of 60 human tumor cell lines. Compound 21 was the most active against all cell lines with log GI50 equal to -5.49 and log LC50 equal to -4.19 and maintained significant percent of growth inhibition on seven cancer cell lines at the concentration of 1 μM. Compound 17 was the second most active and moreover showed interesting selectivity against some cell lines (Lung cancer: A549/ATCC, Melanoma: UACC-257, Ovarian Cancer: ovcar-8 and Renal cancer: RXF 393) at all concentration examined (100-0.01 μM).
- Piras, Sandra,Carta, Antonio,Briguglio, Irene,Corona, Paola,Paglietti, Giuseppe,Luciani, Rosaria,Costi, Maria Paola,Ferrari, Stefania
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p. 169 - 183
(2014/03/21)
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- Homogeneous catalytic hydrogenation of amides to amines
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Hydrogenation of amides in the presence of [Ru(acac)3] (acacH=2,4-pentanedione), triphos [1,1,1-tris- (diphenylphosphinomethyl)ethane] and methanesulfonic acid (MSA) produces secondary and tertiary amines with selectivities as high as 93 % provided that there is at least one aromatic ring on N. The system is also active for the synthesis of primary amines. In an attempt to probe the role of MSA and the mechanism of the reaction, a range of methanesulfonato complexes has been prepared from prepared from [Ru(acac) 3], triphos and MSA, or from reactions of [RuX-(OAc)(triphos)] (X=H or OAc) or [RuH2(CO)(triphos)] with MSA. Crys-tallographically characterised complexes include: [Ru(OAc-κ1O) 2(H2O)-(triphos)], [Ru(OAc-κ2O,O') (CH3SO3-κ1O)(triphos)], [Ru(CH 3SO3-κ1O)2-(H 2O)(triphos)] and [Ru2(μ-CH3SO 3)3-(triphos)2][CH3SO3], whereas other complexes, such as [Ru(OAc-κ1O)(OAc- κ2O,O')(triphos)],[Ru(CH3SO3- κ1O)(CH3SO3-κ2O,O')- (triphos)], H[Ru(CH3SO3-κ1O) 3-(triphos)], [RuH(CH3SO3-κ1O) (CO)-(triphos)] and [RuH(CH3SO3-k2O,O')- (triphos)] have been characterised spectroscopically. The interactions between these various complexes and their relevance to the catalytic reactions are discussed.
- Coetzee, Jacorien,Dodds, Deborah L.,Klankermayer, Jürgen,Brosinski, Sandra,Leitner, Walter,Slawin, Alexandra M. Z.,Cole-Hamilton, David J.
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supporting information
p. 11039 - 11050
(2013/09/02)
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- Selective N-alkylation of amines using nitriles under hydrogenation conditions: Facile synthesis of secondary and tertiary amines
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Nitriles were found to be highly effective alkylating reagents for the selective N-alkylation of amines under catalytic hydrogenation conditions. For the aromatic primary amines, the corresponding secondary amines were selectively obtained under Pd/C-catalyzed hydrogenation conditions. Although the use of electron poor aromatic amines or bulky nitriles showed a lower reactivity toward the reductive alkylation, the addition of NH4OAc enhanced the reactivity to give secondary aromatic amines in good to excellent yields. Under the same reaction conditions, aromatic nitro compounds instead of the aromatic primary amines could be directly transformed into secondary amines via a domino reaction involving the one-pot hydrogenation of the nitro group and the reductive alkylation of the amines. While aliphatic amines were effectively converted to the corresponding tertiary amines under Pd/C-catalyzed conditions, Rh/C was a highly effective catalyst for the N-monoalkylation of aliphatic primary amines without over-alkylation to the tertiary amines. Furthermore, the combination of the Rh/C-catalyzed N-monoalkylation of the aliphatic primary amines and additional Pd/C-catalyzed alkylation of the resulting secondary aliphatic amines could selectively prepare aliphatic tertiary amines possessing three different alkyl groups. According to the mechanistic studies, it seems reasonable to conclude that nitriles were reduced to aldimines before the nucleophilic attack of the amine during the first step of the reaction.
- Ikawa, Takashi,Fujita, Yuki,Mizusaki, Tomoteru,Betsuin, Sae,Takamatsu, Haruki,Maegawa, Tomohiro,Monguchi, Yasunari,Sajiki, Hironao
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supporting information; experimental part
p. 293 - 304
(2012/02/01)
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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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- Ruthenium-catalyzed nitro and nitrile compounds coupling with alcohols: Alternative route for N-substituted amine synthesis
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The one-pot synthesis of N-substituted secondary amines from nitrobenzenes and benzonitriles has been developed (see scheme). This report presents a versatile and simple method for the synthesis of N-substituted amines in excellent yield and high efficiency from nitro and nitrile compounds with alcohols.
- Cui, Xinjiang,Zhang, Yan,Shi, Feng,Deng, Youquan
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supporting information; experimental part
p. 2587 - 2591
(2011/04/12)
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- One-pot reductive mono-n-alkylation of aromatic nitro compounds using nitriles as alkylating reagents
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A one-pot, simple, selective, and efficient protocol for the synthesis of aromatic secondary amines from various nitro arenes and nitriles in the presence of 10% Pd/C catalyst under H2 at atmospheric pressure and ambient temperature in tetrahydrofuran is illustrated. The scope and limitations of this method have been examined.
- Neogi, Subhasish,Naskar, Dinabandhu
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experimental part
p. 1901 - 1915
(2011/07/08)
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- Sulfonato-Cu(salen) complex catalyzed N-arylation of aliphatic amines with aryl halides in water
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A water-soluble sulfonato-Cu(salen) complex catalyzed procedure for the N-arylation of simple aliphatic amines, amino alcohols and amino acids in pure water have been developed. A variety of substituted aryl iodides, bromides and electron-deficient chlorides were found to be applicable, and 1,2-disubstituted benzimidazoles could be prepared easily by a cascade amination/condensation process in this catalytic system.
- Wu, Zhiqing,Zhou, Li,Jiang, Zhaoqiong,Wu, Di,Li, Zhengkai,Zhou, Xiangge
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experimental part
p. 4971 - 4975
(2010/11/03)
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- Microwave-promoted mono-N-alkylation of aromatic amines in water: A new efficient and green method for an old and problematic reaction
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A greener improvement to direct mono-N-alkylation of aromatic amines by alkyl halides was achieved using microwave irradiation in water without any catalyst.
- Marzaro, Giovanni,Guiotto, Adriano,Chilin, Adriana
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supporting information; experimental part
p. 774 - 776
(2010/04/23)
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- Reactions of arenediazonium o-benzenedisulfonimides with aliphatic triorganoindium compounds
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The reaction of various arenediazonium o-benzenedisulfonimides with aliphatic triorganoindium compounds is described. Surprisingly, with triethyl- or tributylindium we obtained N-ethyl- or N-butylanilines, respectively. This is the first case in which, at least formally, the reactive site of a diazonium salt is the nitrogen atom directly bonded to the aromatic ring. In contrast, with trimethylindium we obtained only formaldehyde (aryl)hydrazones. In order to explain the difference between trimethyl- and triethylindium we have proposed some reaction mechanisms, supported by detailed density functional (DFT) calculations. The possible role of diazene/hydrazone tautomerism initially assumed was discarded and therefore three mechanisms for the key step (nucleophilic addition of the trialkylindium to the N=N double bond of diazene) were studied. For the favoured mechanism there is a difference in the energy barriers of 2 kcalmol-1 between the reactions with trimethyl- and triethylindium. This difference is explained on the basis of the different C-In bond energies in the two organometallics and it is assumed to be enough to explain their different behaviour under the experimental conditions. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Barbero, Margherita,Cadamuro, Silvano,Dughera, Stefano,Ghigo, Giovanni
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scheme or table
p. 862 - 868
(2009/04/11)
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- Selective N-monoalkylation of anilines catalyzed by a cationic ruthenium(II) compound
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[(PPh3)2Ru(CH3CN)3Cl][BPh4] has been found to catalyze the selective monoalkylation of anilines by alcohols.
- Naskar, Sipra,Bhattacharjee, Manish
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p. 3367 - 3370
(2008/02/12)
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- Reductive N-alkylation of aromatic amines and nitro compounds with nitriles using polymethylhydrosiloxane
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The potential utility of polymethylhydrosiloxane (PMHS) as a reducing agent for reductive N-alkylation of aromatic amines and nitro compounds using nitriles as an alkylating agent and Pd(OH)2/C as a catalyst is described. The application of this method for the synthesis of several heterocyclic compounds is also reported.
- Reddy, Ch. Raji,Vijeender,Bhusan, P. Bibhuti,Madhavi, P. Phani,Chandrasekhar
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p. 2765 - 2768
(2008/02/03)
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- Reductive monoalkylation of aromatic and aliphatic nitro compounds and the corresponding amines with nitriles
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(Chemical Equation Presented) A simple, selective, rapid, and efficient procedure for the synthesis of secondary amines from the reductive alkylation of either aliphatic or aromatic nitro compounds and the corresponding amines is reported. Ammonium formate is used as the hydrogen source and Pd/C as the hydrogen transfer catalyst. The reaction is carried out at room temperature. The rate differences for the preferential formation of secondary over tertiary products are due to both steric and electronic factors.
- Nacario, Ruel,Kotakonda, Shailaja,Fouchard, David M. D.,Tillekeratne, L. M. Viranga,Hudson, Richard A.
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p. 471 - 474
(2007/10/03)
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- Solid phase synthesis of aryl and heteroaryl amines using the Curtius rearrangement
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An efficient method for the solid phase synthesis of secondary aryl amines and heteroaryl amines was developed. The key step was the formation of aryl or heteroaryl carbamates using the Curtius rearrangement of aryl carboxylic acids with Wang resin as a trapping hydroxyl group. N-alkylation reactions of resin-bound carbamates under the Mitsunobu condition or using sodium hydride gave secondary aryl or heteroaryl amines in good yields. The developed method can be applied in the preparation of libraries containing aryl and heteroaryl amine structures as a pharmacophore.
- Sunami, Satoshi,Sagara, Takeshi,Ohkubo, Mitsuru,Morishima, Hajime
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p. 1721 - 1724
(2007/10/03)
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- Zirconium-mediated intramolecular coupling reactions of unsaturated anilines. Diastereoselective synthesis of azetidines
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Imine complexes of zirconocene, generated by a β-hydrogen abstraction process, which possess a carbon-carbon multiple bond, undergo inter- or intramolecular carbometalation to afford 1,4-cyclohexanediamine or cycloalkylaniline derivatives depending on the relative position of the unsaturated moiety with respect to the imine complex. A new diastereoselective synthesis of azetidines has been developed by treatment of azazirconacyclopentanes with iodine.
- Barluenga, Jose,Sanz, Roberto,Fananas, Francisco J.
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p. 5953 - 5958
(2007/10/03)
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- Facile N-alkylation of anilines with alcohols over raney nickle under microwave irradiation
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The anilines could be easily and selectively N-alkylated with alcohols in the presence of a small amount of Raney nickel and with a greatly shortened period under microwave irradiation. A purely non-thermal effect of microwave was observed in the reaction.
- Jiang, Yu-Lin,Hu, Yu-Qiao,Feng, Shu-Qing,Wu, Ji-Shan,Wu, Zu-Wang,Yuan, Yun-Cheng,Liu, Jun-Min,Hao, Qing-Sheng,Li, De-Peng
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p. 161 - 164
(2007/10/03)
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- Reductive N-monoalkylation of primary aromatic amines
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Primary aromatic amines 1 with a variety of ring substituents are easily converted to their N-monoalkyl derivatives 3 by a simple variation of the sodium borohydride/sulfuric acid/carbonyl compound procedure previously described for their N-permethylations. The procedure is suitable for the α-minodeuterium labelling of the new N-substituent.
- Verardo,Giumanini,Strazzolini,Poiana
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p. 121 - 125
(2007/10/02)
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- A new phase transfer catalyst (PTC) for N-alkylation reactions
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Hexamethylene tetramine bromide HMTA+ Br- - a new phase transfer catalyst is reported for N-Alkylation reactions of industrially important anilides.
- Bisarya,Rao
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p. 3305 - 3313
(2007/10/02)
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- Synthesis and Reaction of Diaminosulfoxonium Salts
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Diaminosulfoxonium salts were prepared by alkylation of sulfonimidamides.Their physical properties were described.Their reaction with bases gave the corresponding ylides and sulfonimidamides.The intramolecular rearrangement of the ylides led to ortho substitution via intermediate cyclohexadienimines.Hydrogen transfer, accompanying rearomatization and the subsequent action of bases gave dihydro-2,1-benzisothiazole derivatives.These ylides were also found to react with aldehydes to afford epoxides in moderate yields.
- Okuma, Kentaro,Higuchi, Naotsugu,Kaji, Shinji,Takeuchi, Hiroshi,Ohta, Hiroshi,et al.
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p. 3223 - 3229
(2007/10/02)
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- Cross Interaction Constants As a Measure of Transition State structure. Part 7. Aminolysis of Alkyl Benzenesulphonates
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Kinetic studies of the reactions of methyl and ethyl benzenesulphonates with anilines and benzylamines in methanol and acetonitrile at 65.0 deg C have been reported.The magnitudes of cross-interaction constants between substituents in the nucleophile (X) and the leaving group (Z),ρxz and βxz, were found to be greater for the ethyl series which indicates a tighter transition state for ethyl rather than methyl derivatives.This unexpected trend has been rationalized by making the assumption that the small electron-donating polar effect, of the α-methyl substituent in the ethyl compounds, requires a tighter transition-state structure in addition to the major effect of steric repulsion on the activation barrier which is present in all SN2 reactions taking place at a carbon centre.
- Lee, Ikchoon,Choi, Young Hoon,Rhyu, Keun Woo,Shim, Chang Sub
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p. 1881 - 1886
(2007/10/02)
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