- Reusable Co-nanoparticles for general and selectiveN-alkylation of amines and ammonia with alcohols
-
A general cobalt-catalyzedN-alkylation of amines with alcohols by borrowing hydrogen methodology to prepare different kinds of amines is reported. The optimal catalyst for this transformation is prepared by pyrolysis of a specific templated material, which is generatedin situby mixing cobalt salts, nitrogen ligands and colloidal silica, and subsequent removal of silica. Applying this novel Co-nanoparticle-based material, >100 primary, secondary, and tertiary amines includingN-methylamines and selected drug molecules were conveniently prepared starting from inexpensive and easily accessible alcohols and amines or ammonia.
- Beller, Matthias,Gawande, Manoj B.,Jagadeesh, Rajenahally V.,Kadam, Ravishankar G.,Li, Xinmin,Ma, Zhuang,Petr, Martin,Zbo?il, Radek,Zhou, Bei
-
p. 111 - 117
(2022/01/06)
-
- PROCESS FOR PREPARATION OF HALOGENATED BENZYLAMINE AND INTERMEDIATES THEROF
-
The present invention provides an improved process for the preparation of halogenated benzylamine having the formula I from halogenated benzonitriles, Formula I wherein, X1 is selected from group consisting of hydrogen, chloro or fluoro, provided atleast one X1 is chloro or fluoro.
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-
Page/Page column 19
(2020/08/13)
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- Chemoselective reduction of nitro and nitrile compounds using an Fe3O4-MWCNTs?PEI-Ag nanocomposite as a reusable catalyst
-
Multi-walled carbon nanotubes (MWNTs) were modified with carboxylic acid functional groups (MWCNTs-(COOH)n) prior to decoration with Fe3O4 nanoparticles. A further modification step by polyethyleneimine (PEI) resulted in Fe3O4-MWCNTs?PEI which provided a suitable platform for coordination and in situ reduction of silver ions to obtain an Fe3O4-MWCNTs?PEI-Ag nanocomposite with highly dispersed Ag nanoparticles. The Fe3O4-MWCNTs?PEI-Ag hybrid material was characterized by various techniques such as Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA), and was used as an efficient catalyst for chemoselective reduction of nitroaromatic and nitrile compounds to their corresponding amines in aqueous solution at ambient temperature. Nitrofurazone, a cytotoxic antibiotic, as a non-aromatic example was also reduced selectively at the nitro group without reduction of the other functionalities in the presence of Fe3O4-MWCNTs?PEI-Ag. The catalyst was magnetically recoverable and maintained its activity for at least six cycles without considerable loss of efficiency.
- Ansari, Sara,Khorshidi, Alireza,Shariati, Shahab
-
p. 3554 - 3565
(2020/02/04)
-
- Facile synthesis of controllable graphene-co-shelled reusable Ni/NiO nanoparticles and their application in the synthesis of amines under mild conditions
-
The primary objective of many researchers in chemical synthesis is the development of recyclable and easily accessible catalysts. These catalysts should preferably be made from Earth-abundant metals and have the ability to be utilised in the synthesis of pharmaceutically important compounds. Amines are classified as privileged compounds, and are used extensively in the fine and bulk chemical industries, as well as in pharmaceutical and materials research. In many laboratories and in industry, transition metal catalysed reductive amination of carbonyl compounds is performed using predominantly ammonia and H2. However, these reactions usually require precious metal-based catalysts or RANEY nickel, and require harsh reaction conditions and yield low selectivity for the desired products. Herein, we describe a simple and environmentally friendly method for the preparation of thin graphene spheres that encapsulate uniform Ni/NiO nanoalloy catalysts (Ni/NiO?C) using nickel citrate as the precursor. The resulting catalysts are stable and reusable and were successfully used for the synthesis of primary, secondary, tertiary, and N-methylamines (more than 62 examples). The reaction couples easily accessible carbonyl compounds (aldehydes and ketones) with ammonia, amines, and H2 under very mild industrially viable and scalable conditions (80 °C and 1 MPa H2 pressure, 4 h), offering cost-effective access to numerous functionalized, structurally diverse linear and branched benzylic, heterocyclic, and aliphatic amines including drugs and steroid derivatives. We have also demonstrated the scale-up of the heterogeneous amination protocol to gram-scale synthesis. Furthermore, the catalyst can be immobilized on a magnetic stirring bar and be conveniently recycled up to five times without any significant loss of catalytic activity and selectivity for the product.
- Cui, Zhibing,Liu, Jianguo,Liu, Qiying,Ma, Longlong,Singh, Thishana,Wang, Chenguang,Wang, Nan,Zhu, Yuting
-
supporting information
p. 7387 - 7397
(2020/11/19)
-
- Synthesis of oxalamides by acceptorless dehydrogenative coupling of ethylene glycol and amines and the reverse hydrogenation catalyzed by ruthenium
-
A sustainable, new synthesis of oxalamides, by acceptorless dehydrogenative coupling of ethylene glycol with amines, generating H2, homogeneously catalyzed by a ruthenium pincer complex, is presented. The reverse hydrogenation reaction is also accomplished using the same catalyst. A plausible reaction mechanism is proposed based on stoichiometric reactions, NMR studies, X-ray crystallography as well as observation of plausible intermediates.
- Ben-David, Yehoshoa,Diskin-Posner, Yael,Milstein, David,Zhou, Quan-Quan,Zou, You-Quan
-
p. 7188 - 7193
(2020/07/23)
-
- Design, synthesis and the structure-activity relationship of agonists targeting on the ALDH2 catalytic tunnel
-
ALDH2, a key enzyme in the alcohol metabolism process, detoxifies several kinds of toxic small molecular aldehydes, which induce severe organ damages. The development of novel Alda-1 type ALDH2 activators was mostly relied on HTS but not rational design so far. To clarify the structure–activity relationship (SAR) of the skeleton of Alda-1 analogs by synthesis of the least number of analogs, we prepared 31 Alda-1 analogs and 3 isoflavone derivatives and evaluated for their ALDH2-activating activity. Among these, the ALDH2-activating activity of mono-halogen-substituted (Cl and Br) N-piperonylbenzamides 3b and 3 k, and non-aromatic amides 8a-8c, were 1.5–2.1 folds higher than that of Alda-1 at 20 μM. The relationship between binding affinity in computer aided molecular docking model and the ALDH2-activating activity assays were clarified as follows: for Alda-1 analogs, with the formation of halogen bonds, the enzyme-activating activity was found to follow a specific regression curve within the range between ?5 kcal/mol and ?4 kcal/mol. For isoflavone derivatives, the basic moiety on the B ring enhance the activating activity. These results provide a new direction of utilizing computer-aided modeling to design novel ALDH2 agonists in the future.
- Cheng, Ming-Che,Lo, Wei-Chi,Chang, Yu-Wen,Lee, Shoei-Sheng,Chang, Chia-Chuan
-
-
- Green and convenient protocols for the efficient reduction of nitriles and nitro compounds to corresponding amines with NaBH4 in water catalyzed by magnetically retrievable CuFe2O4 nanoparticles
-
Abstract: In this study, firstly, CuFe2O4 nanoparticles were prepared by a simple operation. The structure of the mentioned nanoparticles was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, inductively coupled plasma-optical emission spectrometry, vibrating sample magnetometer and also Brunauer–Emmett–Teller and Barrett–Joyner–Halenda analyses. The prepared magnetically copper ferrite nanocomposite was successfully applied as a simple, cost-effective, practicable, and recoverable catalyst on the green, highly efficient, fast, base-free, and ligand-free reduction of nitriles and also on the affordable and eco-friendly reduction of nitro compounds with the broad substrate scope to the corresponding amines with NaBH4 in water at reflux in high to excellent yields. Graphical abstract: [Figure not available: see fulltext.].
- Zeynizadeh, Behzad,Mohammad Aminzadeh, Farkhondeh,Mousavi, Hossein
-
-
- A ppm level Rh-based composite as an ecofriendly catalyst for transfer hydrogenation of nitriles: Triple guarantee of selectivity for primary amines
-
Hydrogenation of nitriles to afford amines under mild conditions is a challenging task with an inexpensive heterogeneous catalyst, and it is even more difficult to obtain primary amines selectively because of the accompanying self-coupling side reactions. An efficient catalytic system was designed as Fe3O4@nSiO2-NH2-RhCu@mSiO2 to prepare primary amines through the transfer hydrogenation of nitrile compounds with economical HCOOH as the hydrogen donor. The loading of rhodium in the catalyst could be at the ppm level, and the TOF reaches 6803 h-1 for Rh. This catalytic system has a wide substrate range including some nitriles that could not proceed in the previous literature. The experimental results demonstrate that the excellent selectivity for primary amines is guaranteed by three tactics, which are the strong active site, the inhibition of side products by the hydrogen source and the special pore structure of the catalyst. In addition, the catalyst could be reused ten times without activity loss through convenient magnetic recovery.
- Liu, Lei,Li, Jifan,Ai, Yongjian,Liu, Yuhong,Xiong, Jialiang,Wang, Hongdong,Qiao, Yijun,Liu, Wenrui,Tan, Shanchao,Feng, Shaofei,Wang, Kunpeng,Sun, Hongbin,Liang, Qionglin
-
p. 1390 - 1395
(2019/03/26)
-
- Chemo-selective reduction of nitro and nitrile compounds using Ni nanoparticles immobilized on hyperbranched polymer-functionalized magnetic nanoparticles
-
The nitro and nitrile groups in aromatic and aliphatic compounds containing various reducible substituents such as carboxylic acid, ketone, aldehyde and halogen are selectively reduced to the corresponding amines in water as a green solvent with excellent yields by employing NaBH4 in the presence of Fe3O4@PAMAM/Ni(0)-b-PEG nanocatalyst. The morphology and structural features of the catalyst were characterized using various microscopic and spectroscopic techniques. The designed catalyst system because of it being covered with hydrophilic polymers is soluble in a wide range of solvents (e.g. water and ethanol) and suitable for immobilizing and stabilizing Ni nanoparticles in aqueous mediums. In addition, the catalyst can be easily recovered from a reaction mixture by applying an external magnetic field and can be reused up to six runs without significant loss of activity.
- Tabatabaei Rezaei, Seyed Jamal,Mashhadi Malekzadeh, Asemeh,Poulaei, Sima,Ramazani, Ali,Khorramabadi, Hossein
-
-
- Synthesis of cobalt nanoparticles by pyrolysis of Vitamin B12: A non-noble-metal catalyst for efficient hydrogenation of nitriles
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A facile preparation of vitamin B12-derived carbonaceous cobalt particles supported on ceria is reported. The resulting composite material is obtained upon wet impregnation of ceria with natural cyanocobalamin and consecutive pyrolysis under inert conditions. The novel catalyst shows good to excellent performance in the industrially relevant heterogeneous hydrogenation of nitriles to the corresponding primary amines.
- Ferraccioli, Raffaella,Borovika, Diana,Surkus, Annette-Enrica,Kreyenschulte, Carsten,Topf, Christoph,Beller, Matthias
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p. 499 - 507
(2018/02/07)
-
- Synthesis and characterization of copper nanoparticles on walnut shell for catalytic reduction and C-C coupling reaction
-
Walnut shell-stabilized copper nanoparticles (CuNP/WS) were successfully prepared by a simple reaction of copper sulfate and Sodium borohydride. Formation of copper nanoparticles in this bio-nanocomposite was observed by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscope (EDX). CuNP/WS was found to be an efficient, inexpensive, easy to prepare, green and reusable catalyst in the reduction of aromatic nitro and nitrile compounds to their corresponding amines with NaBH4 at 35 °C in aqueous medium. We continued our studies on the application of this nanocomposite in the classic Ullman reaction to synthesize biaryl. This method has the advantages of high yields, elimination of expensive stabilizer and homogeneous catalysts, simple methodology and easy work up. The catalyst can be recovered from the reaction mixture and reused several times without any significant loss of catalytic activity.
- Zamani, Asghar,Poursattar Marjani, Ahmad,Nikoo, Abbas,Heidarpour, Mojtaba,Dehghan, Ahmad
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p. 176 - 181
(2018/09/25)
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- Selective Hydrogenation of Cyclic Imides to Diols and Amines and Its Application in the Development of a Liquid Organic Hydrogen Carrier
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Direct hydrogenation of a broad variety of cyclic imides to diols and amines using a ruthenium catalyst is reported here. We have applied this strategy toward the development of a new liquid organic hydrogen carrier system based on the hydrogenation of bis-cyclic imide that is formed by the dehydrogenative coupling of 1,4-butanediol and ethylenediamine using a new ruthenium catalyst. The rechargeable system has a maximum gravimetric hydrogen storage capacity of 6.66 wt%.
- Kumar, Amit,Janes, Trevor,Espinosa-Jalapa, Noel Angel,Milstein, David
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supporting information
p. 7453 - 7457
(2018/06/08)
-
- Cobalt complex, preparation method thereof, and application thereof in selective catalysis of transfer hydrogenation reaction of cyano group
-
The invention discloses a cobalt complex, a preparation method thereof, and an application thereof in the selective catalysis of a transfer hydrogenation reaction of a cyano group. The structural formula of the cobalt complex is represented by formula I. The cobalt complex is prepared through a reaction of a cobalt salt and an NNP ligand or a PNP ligand under the protection of an inert atmosphere;and the chemical formula of the cobalt salt is CoX12, wherein X1 represents halogen, a sulfate radical, a perchlorate radical, a hexafluorophosphate radical, a hexafluoroantimonate radical, a tetrafluoroborate radical, a trifluoromethanesulfonate radical or a tetra(pentafluorophenyl)borate radical. The cobalt complex can be used in the selective catalysis of the transfer hydrogenation reaction ofthe cyano group to obtain a primary amine compound, a secondary amine compound and a tertiary amine compound, the primary amine compound, the secondary amine compound and the tertiary amine compoundare important intermediates in a series of subsequent functionalizing reactions, and the cobalt complex has a very high catalysis activity, and has great research values and a great application prospect.
- -
-
Paragraph 0157-0160
(2018/05/07)
-
- Selective Hydrogenation of Nitriles to Primary Amines by using a Cobalt Phosphine Catalyst
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A general procedure for the catalytic hydrogenation of nitriles to primary amines by using a non-noble metal-based system is presented. Co(acac)3 in combination with tris[2-(dicyclohexylphosphino)ethyl]phosphine efficiently catalyzes the selective hydrogenation of a wide range of (hetero)aromatic and aliphatic nitriles to give the corresponding amines.
- Adam, Rosa,Bheeter, Charles Beromeo,Cabrero-Antonino, Jose R.,Junge, Kathrin,Jackstell, Ralf,Beller, Matthias
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p. 842 - 846
(2017/03/17)
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- NNP-Type Pincer Imidazolylphosphine Ruthenium Complexes: Efficient Base-Free Hydrogenation of Aromatic and Aliphatic Nitriles under Mild Conditions
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A series of seven novel NImNHP-type pincer imidazolylphosphine ruthenium complexes has been synthesized and fully characterized. The use of hydrogenation of benzonitrile as a benchmark test identified [RuHCl(CO)(NImNHPtBu)] as the most active catalyst. With its stable Ru-BH4 analogue, in which chloride is replaced by BH4, a broad range of (hetero)aromatic and aliphatic nitriles, including industrially interesting adiponitrile, has been hydrogenated under mild and base-free conditions.
- Adam, Rosa,Alberico, Elisabetta,Baumann, Wolfgang,Drexler, Hans-Joachim,Jackstell, Ralf,Junge, Henrik,Beller, Matthias
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p. 4991 - 5002
(2016/04/05)
-
- Mild and Selective Cobalt-Catalyzed Chemodivergent Transfer Hydrogenation of Nitriles
-
Herein, we describe a selective cobalt-catalyzed chemodivergent transfer hydrogenation of nitriles to synthesize primary, secondary, and tertiary amines. The solvent effect plays a key role for the selectivity control. The general applicability of this procedure was highlighted by the synthesis of more than 70 amine products bearing various functional groups in high chemoselectivity. Moreover, this mild system achieved >2000 TONs (turnover numbers) for the transfer hydrogenation of nitriles.
- Shao, Zhihui,Fu, Shaomin,Wei, Mufeng,Zhou, Shaolin,Liu, Qiang
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supporting information
p. 14653 - 14657
(2016/11/23)
-
- Active and Recyclable Catalytic Synthesis of Indoles by Reductive Cyclization of 2-(2-Nitroaryl)acetonitriles in the Presence of Co-Rh Heterobimetallic Nanoparticles with Atmospheric Hydrogen under Mild Conditions
-
A cobalt-rhodium heterobimetallic nanoparticle-catalyzed reductive cyclization of 2-(2-nitroaryl)acetonitriles to indoles has been achieved. The tandem reaction proceeds without any additives under the mild conditions (1 atm H2 and 25 °C). This procedure could be scaled up to the gram scale. The catalytic system is significantly stable under these reaction conditions and could be reused more than ten times without loss of catalytic activity.
- Choi, Isaac,Chung, Hyunho,Park, Jang Won,Chung, Young Keun
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p. 5508 - 5511
(2016/11/17)
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- A method for the production of primary amines
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The invention relates to the field of chemical industry and particularly relates to a method for preparing primary amine by using the raw materials including halogenated hydrocarbon (or hydrocarbon alcohol sulfonate) and ammonia water (or formamide). The method comprises the following three steps: (1) imidization: 3,4-diarylfuran-2,5-diketone (I) reacts with ammonia (or formamide) and the like to obtain 3,4-diaryl-1H-pyrrole-2,5-diketone (II); (2) N-hydrocarbylation: 3,4-diaryl-1H-pyrrole-2,5-diketone (II) generates an N-hydrocarbylation reaction with halogenated hydrocarbon (or hydrocarbon alcohol sulfonate) in the presence of alkali to obtain N-hydrocarbyl-3,4-diaryl-1H-pyrrole-2,5-diketone (III); and (3) hydrolysis: N-hydrocarbyl-3,4-diaryl-1H-pyrrole-2,5-diketone (III) is subjected to alkali hydrolysis to obtain primary amine and the generated 2,3-diaryl maleate is subjected to acid treatment and automatic ring closing to form 3,4-diaryl furan-2,5-diketone (I) which is subjected to imidization and directly applied to the N-hydrocarbylation reaction. The method provided by the invention has the characteristics that the 3,4-diaryl furan-2,5-diketone can be circularly used at a high recovery rate, the molar ratio of the raw materials is low, and the yield of the product primary amine is high.
- -
-
Paragraph 0217
(2016/10/09)
-
- Effect of novel triazole-amino acid hybrids on growth and virulence of Candida species: in vitro and in vivo studies
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The increasing incidence of human candidiasis and the tendency of Candida species to become resistant to existing chemotherapies are well-recognized health problems. The present study demonstrates the successful synthesis of novel triazole-amino acid hybrids with potent in vitro and in vivo inhibitory activity against Candida species. Particularly, compounds 68 and 70 showed potent in vitro activity against fluconazole (FLC) resistant as well as sensitive clinical isolates of Candida albicans. Time kill curve analysis of lead inhibitors 68 and 70 showed their fungistatic nature. Secretion of hydrolytic enzymes, mainly proteinases and phospholipases, decreased considerably in the presence of 68 and 70 indicating their interference in fungal virulence. TEM analysis of Candida cells exposed to compounds 68 and 70 clearly showed morphological changes and intracellular damage as their possible mode of action. A preliminary mechanistic study carried out on the two most effective inhibitors (68 and 70) revealed the inhibition of ergosterol biosynthesis thereby causing the cells to lose their integrity and viability. The selected compounds did not show significant cytotoxicity up to a concentration of 200 μg mL?1 in the HEK293 cell line. An in silico analysis of 68 and 70 binding to a modeled C. albicans CYP51 showed critical H-bonding as well as hydrophobic interactions with the important active site residues indicating the basis of their anti-Candida role. Studies on the larvae of Galleria mellonella showed that the selected inhibitors (68 and 70) were non-toxic, did not provoke an immune response and significantly reduced Candida proliferation in vivo.
- Aneja, Babita,Irfan, Mohammad,Kapil, Charu,Jairajpuri, Mohamad Aman,Maguire, Ronan,Kavanagh, Kevin,Rizvi, M. Moshahid A.,Manzoor, Nikhat,Azam, Amir,Abid, Mohammad
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p. 10599 - 10619
(2016/11/30)
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- Monocyclic β-lactam and unexpected oxazinone formation: synthesis, crystal structure, docking studies and antibacterial evaluation
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Novel monocyclic β-lactam derivatives bearing aryl, phenyl and heterocyclic rings were synthesized as possible antibacterial agents. Cyclization of imines (3h, 3t) with phenylacetic acid in the presence of phosphoryl chloride and triethyl amine did not afford the expected β-lactams. Instead, highly substituted 1,3-oxazin-4-ones (4h, 4t) were isolated as the only product and confirmed by single crystal X-ray analysis of 4t. The results of antibacterial activity showed that compound 4l exhibited considerable antibacterial activity with MIC and MBC values of 62.5 μg/mL against Klebsiella pneumoniae. Cytotoxicity assay on Chinese Hamster Ovary (CHO) cell line revealed non-cytotoxic behavior of compounds 4d, 4h, 4k and 4l up to 200 μg/mL conc. Molecular docking was performed for compound 4l with penicillin binding protein-5 to identify the nature of interactions. The results of both in silico and in vitro evaluation provide the basis for compound 4l to be carried as a potential lead molecule in the drug discovery pipeline against bacterial infections.
- Aneja, Babita,Irfan, Mohammad,Hassan, Md. Imtaiyaz,Prakash, Amresh,Yadava, Umesh,Daniliuc, Constantin G.,Zafaryab, Md.,Rizvi, M. Moshahid A.,Azam, Amir,Abid, Mohammad
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p. 834 - 852
(2016/07/07)
-
- Preparation and characterization of primary amines by potassium borohydride-copper chloride system from nitriles
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Nitriles undergo reduction to primary amines under optimized conditions at 50 °C using 0.25 equiv of copper chloride and 3.0 equiv of potassium borohydride in 80 % isopropanol. The aromatic and aralkyl nitriles could be effectively reduced in yield ranging from 60 to 90 %.
- Jiang, Han,Hu, Jialei,Xu, Xinliang,Zhou, Yifeng
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p. 3564 - 3566
(2015/12/30)
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- Experimental and computational study of 6- Exo and 7- Endo cyclization of aryl radicals followed by Tandem SRN1 Substitution
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The reaction of N-allyl-N-(2-halobenzyl)-acetamides and derivatives was investigated in liquid ammonia under irradiation with the nucleophiles Me 3Sn-, Ph2P- and O 2NCH2-. Following this procedure, novel substituted 2-acetyl-1,2,3,4-tetrahydroisoquinolines and substituted 2-acetyl-2,3,4,5-tetrahydro-1H-benzo[c]azepines were obtained in good yields. These reactions are proposed to occur through the intermediacy of aryl radicals, which by intramolecular 6-exo or 7-endo attack to a double bond cyclize to give aliphatic radicals, which react along the propagation steps of the S RN1 chain cycle to afford the cyclic substituted compounds as main products. The reactions were modeled with DFT methods, which provide a rational understanding that relates the product distribution to the structure of the aliphatic radicals proposed as intermediates and the kinetic of their formation.
- Peisino, Lucas E.,Pierini, Adriana B.
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p. 4719 - 4729
(2013/07/11)
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- A metal-free catalytic system for the oxidation of benzylic methylenes and primary amines under solvent-free conditions
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Iodine-pyridine-tert-butylhydroperoxide is developed as a green and efficient catalytic system for the oxidation of benzylic methylenes to ketones and primary amines to nitriles. The reaction conditions are quite mild and environmentally benign, no transition metals, organic solvents or hazard reagents being needed. The oxidation of benzylic methylenes gave the corresponding ketones in excellent yields with complete chemoselectivity, while the oxidation of primary amines was complete in several minutes, affording various nitriles in moderate to good yields.
- Zhang, Jintang,Wang, Zhentao,Wang, Ye,Wan, Changfeng,Zheng, Xiaoqi,Wang, Zhiyong
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supporting information; scheme or table
p. 1973 - 1978
(2010/06/15)
-
- Highly chemoselective hydrogenation method using novel finely dispersed palladium catalyst on silk-fibroin: Its preparation and activity
-
A palladium-fibroin complex (Pd/Fib) was prepared by soaking silk-fibroin in MeOH solution of Pd(OAc)2 for 2 days (under Ar atmosphere) - 4 days (under air). Pd(OAc)2 was gradually absorbed by fibroin and the rapid reduction of fibroin conjugated Pd(OAc)2 proceeded with MeOH as a reductant at room temperature to be the Pd(0) complex. Pd/Fib catalyzed chemoselective hydrogenation of acetylenes, olefins and azides in the presence of aromatic ketones and aldehydes, halides, N-Cbz protective groups and benzyl esters which are readily hydrogenated using Pd/C or Pd/C(en) as a catalyst.
- Ikawa, Takashi,Sajiki, Hironao,Hirota, Kosaku
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p. 2217 - 2231
(2007/10/03)
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- Reduction of amides with NaBH4 in diglyme at 162°C
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High temperature (162°C) reductions of aromatic amides were studied to extend the useful range of functional group transformations by NaBH4. Primary aromatic amides were reduced to the amines with NaBH4-diglyme at 162°C. Reduction proceeds via fast initial loss of hydrogen, followed by formation of the corresponding nitrile, which is then more slowly reduced to the amine. N-Methylbenzamide is not reduced under these conditions, but it is reduced to benzylmethylamine when LiCl is added to NaBH4-diglyme at 162°C. LiCl addition raised the rate of primary aromatic amide and aromatic nitrile conversions to both the nitrile, first, and the amine. An intermediate was isolated from the reaction of N-benzylformamide with NaBH4-LiCl in diglyme at 162°C. It was examined by 1H NMR, atomic absorption, IR and thermal decomposition. Possible structures are proposed. A mechanism for the reduction of primary aromatic amides is proposed based on the initial evolution of one mole equivalent of hydrogen and formation of the nitrile prior to further reduction to amine.
- Zhu, Hua-Jie,Lu, Kai-Tao,Sun, Guang-Ri,He, Jin-Bao,Li, Hai-Qing,Pittman Jr., Charles U.
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p. 409 - 413
(2007/10/03)
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- Preparation of silk fibroin-supported Pd(0) catalyst for chemoselective hydrogenation: Reduction of palladium(II) acetate by methanol on the protein
-
The Pd/fibroin (Fib) was easily prepared by the auto-reduction of the silk-fibroin conjugated Pd(OAc)2 using MeOH as a solvent and a reductant and exhibited good chemoselectivity in the hydrogenation of olefins and azides in the presence of aromatic carbonyls and/or halogens or an O-benzyl protective group.
- Sajiki, Hironao,Ikawa, Takashi,Yamada, Hiromi,Tsubouchi, Kozo,Hirota, Kosaku
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p. 171 - 174
(2007/10/03)
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- THIENOPYRIMIDINES
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Thienopyrimidines of the formula (I) and their physiologically acceptable salts, in which R1, R2 and X are as defined in claim 1, exhibit phosphodiesterase V inhibition and can be employed for the treatment of illnesses of the cardiovascular system and for the treatment and/or therapy of impotence.
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- Rapid reduction of nitriles to primary amines with nickel boride at ambient temperature
-
Reduction of a variety of nitriles to their corresponding primary amines can be achieved with nickel boride generated in situ in dry ethanol at ambient temperature. The reductions are very rapid and chemoselective.
- Khurana, Jitender M.,Kukreja, Gagan
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p. 1265 - 1269
(2007/10/03)
-
- 2-aminobenzoxazole derivatives and combinatorial libraries thereof
-
The present invention relates to novel 2-aminobenzoxazole derivative compounds of the following formula: wherein R1 to R4 and Z have the meanings provided herein. The invention further relates to combinatorial libraries containing two or more such compounds, as well as methods of preparing 2-aminobenzoxazole derivative compounds.
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-
- 2-aminopyridine derivatives and combinatorial libraries thereof
-
The present invention relates to novel 2-aminopyridine derivative compounds of the following formula: wherein R1to R5have the meanings provided herein. The invention further relates to combinatorial libraries containing two or more such compounds, as well as methods of preparing 2-aminopyridine derivative compounds.
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-
- Aminoborohydrides. 12. Novel tandem SNAr amination-reduction reactions of 2-halobenzonitriles with lithium N,N-dialkylaminoborohydrides
-
A novel tandem amination-reduction reaction has been developed in which 2-(N,N-dialkylamino)benzylamines are generated from 2-halobenzonitriles and lithium N,N-dialkylaminoborohydride (LAB) reagents. These reactions are believed to occur through a tandem SNAr amination-reduction mechanism wherein the LAB reagent promotes halide displacement by the N,N-dialkylamino group, and the nitrile is subsequently reduced. This one-pot procedure is complimentary to existing synthetic methods and is an attractive synthetic tool for the nucleophilic aromatic substitution of halobenzenes with less nucleophilic amines. The (N,N-dialkylamino)benzylamine products of this reaction are easily isolated after a simple aqueous workup procedure in very good to excellent yields.
- Thomas,Collins,Cuzens,Spiciarich,Goralski,Singaram
-
p. 1999 - 2004
(2007/10/03)
-
- Anti-viral method
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PCT No. PCT/US97/07431 Sec. 371 Date Jan. 6, 1999 Sec. 102(e) Date Jan. 6, 1999 PCT Filed May 2, 1997 PCT Pub. No. WO97/41846 PCT Pub. Date Nov. 13, 1997The present invention provides compounds which inhibit an envelope virus by inhibiting the fusion of the virus with the host cell. The virus may be inhibited in an infected cell, a cell susceptible of infection or a mammal in need thereof.
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- Urea, thiourea and guanidine compounds and their use as anti-viral agents
-
The present invention provides compounds which inhibit an envelope virus by inhibiting the fusion of the virus with the host cell. The virus may be inhibited in an infected cell, a cell susceptible of infection or a mammal in need thereof.
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- Substituted benzimidazoles useful as angiotension II receptor antagonists
-
Angiotensin II receptor antagonists having the formula: STR1 which are useful in regulating hypertension and in the treatment of congestive heart failure, renal failure, and glaucoma, pharmaceutical compositions including these antagonists, and methods of using these compounds to produce angiotensin II receptor antagonism in mammals.
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- Process for producing benzylamines
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A process for producing a benzylamine which comprises reacting a benzyl halide with an aqueous ammonia solution in the presence of an aromatic aldehyde represented by the formula: STR1 wherein R represents a hydrogen atom, a halogen atom or a lower alkyl group, and n is 1 or 2, separating an oily substance from the reaction mixture, and treating the oily substance with a mineral acid.
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- Novel Reduction of Carboxylic Acids, Esters, Amides and Nitriles Using Samarium Diiodide in the Presence of Water
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Aromatic carboxylic acids, esters, amides, nitriles, chlorides, ketones and nitro compounds were rapidly reduced by the samarium diiodide-H2O system to the corresponding products at room temperature in good yields.
- Kamochi, Yasuko,Kudo, Tadahiro
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p. 1495 - 1498
(2007/10/02)
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- Reductions of carboxylic acids and their derivatives using samarium diiodide-acid system
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Carboxylic acid was converted to alcohol in a facile-rapid reduction using samarium diiodide in protic solvent under a basic or acidic medium at room temperature in high yield. A similar reaction of ester and anhydride reduced to the corresponding alcohol as the major products and nitrile afforded amine. Amide was rapidly reduced under a basic medium to afford alcohol, but the reduction with samarium diiodide-acid system of amide gave aldehyde in quantitative yield.
- Kamochi,Kudo
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p. 4301 - 4312
(2007/10/02)
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- Process for the preparation of amines
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Reaction products of oxo compounds and amines or ammonia, in which at least one substituent is aromatic and monosubstituted to trisubstituted by halogen, can be catalytically hydrogenated to the respective amines, the halogen essentially being completely retained if an Ni-containing or Co-containing catalyst is employed and the reaction is carried out in the presence of organic sulphur compounds.
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- Preparing 2-chlorobenzylamine from 2-chlorobenzylchloride via 2-chlorobenzylphthalimide
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2-Chlorobenzylamine is prepared from 2-chlorobenzylchloride in a two-step process. In the first step, 2-chlorobenzylchloride is reacted with alkali metal phthalimide, preferably formed in situ from potassium carbonate and phthalimide, to form the novel intermediate 2-chlorobenzylphthalimide. In the second step, the phthalimide ring of the 2-chlorobenzylphthalimide is cleaved to form 2-chlorobenzylamine. The first step is preferably carried out in an unreactive solvent at 60° C. to reflux temperature, for example, for 1 to 10 hours. The solvent is very preferably dimethylformamide which is advantageously recovered and used again as solvent in the conversion of 2-chlorobenzylchloride to 2-chlorobenzylphthalimide. The second step consists essentially, for example, of hydrazinolysis or hydrolysis. When the second step consists essentially of hydrazinolysis, the 2-chlorobenzylphthalimide is reacted with hydrazine to form 2-chlorobenzylamine and phthalylhydrazide, and the 2-chlorobenzylamine is separated by reacting with acid to form soluble amine salt, filtering out the phthalylhydrazide and then reacting the amine salt with base to convert it to the free amine. When the second step consists essentially of hydrolysis, the hydrolysis can be carried out in one step with alkali metal hydroxide or inorganic acid or in two steps, for example, with hydrolysis with alkali metal hydroxide followed by hydrolysis with inorganic acid. The hydrolysis is suitably carried out at temperatures of 60° C. to reflux temperature utilizing base and acid strengths ranging from 5% to saturated. Preferred hyrdolyzing agents are 40-60% aqueous KOH for one step base hydrolysis, 40-60% aqueous sulfuric acid for one step acid hydrolysis and 10-30% aqueous KOH followed by a mixture of water and concentrated HCl in a volume ratio ranging from 0.5:1 to 2:1 for the two-step base/acid hydrolysis. A second step consisting essentially of hydrolysis is preferred over a second step consisting essentially of hydrazinolysis not only for safety reasons but also because phthalic acid or a mixture of this with 2-chlorobeznylphthalamic acid can be recovered as by-product or by-product derivative which, contrary to the hydrazinolysis by product, phthalylhydrazide, are readily, respectively, converted to phthalimide and 2-chlorobenzylphthalimide by reaction with concentrated aqueous ammonium hydroxide. The phthalimide is useful in the in situ reaction in the first step to form 2-chlorobenzylphthal-imide. 2-Chlorobenzylphthalimide which is introduced with phthalimide into said first step becomes part of the product of the first step.
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- Diphenyl-methane compounds useful in the treatment of diseases caused by aggregation of platelets or formation of thrombus
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A new diphenyl-methane derivative is useful to inhibit agglomeration of blood and is defined by the formula, including a diphenylethylene derivative and a benzophenone oxime ether derivative. STR1 in which R1 and R2 each are hydrogen, hydroxyl or a lower alkoxy, U is =CXY or =N--O--W, X is hydrogen, cyano or --COR6, R6 being hydroxyl or an amino, Y is --R10--COOR3, R3 being hydrogen or a lower alkoxy, R10 being an alkylene having 1 to 3 carbon atoms, straight or branched, --CO--NR4R5, R4 and R5 each being hydrogen, a lower alkyl or a lower arylalkyl, --CH2--NHSO2--C6H5 or --C(R8)=NR7, R7 being a lower alkoxy or an aryl, R8 is --VR9, V being oxygen, sulfur or nitrogen, R9 being an alkyl or an aryl, W is --CH2--CO--CH2--COOR13, R13 being hydrogen or a lower alkyl, --CH2--C(C=NOR14)--CH2--COOR15, R15 being hydrogen or a lower alkyl, R14 being a lower alkyl, --CH(CN)--(CH2)q--COOR16, R16 being hydrogen or a lower alkyl, q being an integer of 1 to 3, or --(CH2)p--Z, Z being --SH, --SCN or a monovalent group derived from a five- or six-membered ring which may be substituted by a ring having one or more sulfur atoms in the ring, p being 1 or 2.
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- Hydroxy-group Participation in the Hydrolysis of Amides and its Effective Concentration in the Absence of Strain Effects
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Rate constants are reported for the alkaline- and acid-catalysed hydrolysis of endo-6-hydroxybicycloheptane-endo-2-carboxamides in aqueous solution.The product of the acid-catalysed reaction is endo-6-hydroxybicycloheptane-endo-2-carboxylic acid lactone and this lactone is also formed as an intermediate in alkaline solution before giving the hydroxy-acid anion as the product.The effective concentration of the intramolecular alkoxide ion group is ca. 1E8M.This is in good agreement with the maximum entropic advantage predicted for intramolecular reactions as the system is thought to be free of major strain energy and solvation effects.Variation of substituents in the amine leaving group gives a βlg value of +0.30 for the hydroxide-ion-catalysed lactonisation reaction.This is interpreted in terms of rate-limiting breakdown of the tetrahedral intermediate in which there is cconsiderable positive charge on the amine nitrogen.Mechanisms consistent with this involve either proton transfer from water to the amine nitrogen occuring synchronously with carbon-nitrogen bond fission or a stepwise process in which the nitrogen of the tetrahedral intermediate is fully protonated and the rate-limiting step is either diffusion apart of this intermediate and hydroxide ion or collapse of this intermediate with hydroxide ion acting as a 'spectator'.The βlg value for the acid-catalysed lactonisation reaction is 0.0.
- Morris, Jeffrey J.,Page, Michael I.
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p. 679 - 684
(2007/10/02)
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