- A saccharinate-bridged palladacyclic dimer with a Pd-Pd bond: Experimental and molecular docking studies of the interaction with DNA and BSA and in vitro cytotoxicity against human cancer cell lines
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A new palladacyclic dimer [Pd2((C,N)L)2(μ-Sac)2] (1), in which L: C14H11NBr and sac: the saccharinate ligand, has been synthesized and completely characterized. X-ray crystallography has been used to determine the single crystal structure of this Pd(ii) complex. In this dimer, two palladium(ii) centers are bridged by a saccharinate anion, which is coordinated to the cyclopalladated units as a bidentate (N- and carbonyl O-atoms) ligand. According to DNA binding studies (UV-Vis spectroscopy, emission titration and viscosity measurements), the Pd(ii) complex interacts with calf-thymus DNA (CT-DNA) through a groove binding mode with a binding affinity on the order of 105. Furthermore, UV-Vis and fluorescence emission spectroscopy have been used to monitor the binding of the complex to bovine serum albumin (BSA). The complex is mainly located in site I of the protein, based on the competitive experiments using Warfarin, Ibuprofen and Digoxin as site markers. The results of molecular docking confirmed the experimental data. Finally, the in vitro cytotoxicity of sodium saccharin, ligand LH (C14H12NBr), complex 1 and cisplatin against cervical cancer (HeLa), lung cancer (A549) and breast cancer (MCF-7) cell lines has been studied. The complexation process has significantly improved the anticancer activity, as the IC50 values show. Furthermore, complex 1 has been tested against NIH normal fibroblast cells. Therefore, based on the SI definition, 1 can be assigned as a selective compound against cancer cells.
- Karami, Kazem,Alinaghi, Moloud,Amirghofran, Zahra,Lipkowski, Janusz,Momtazi-Borojeni, Amir Abbas
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Read Online
- Half-Sandwich Ruthenium Complexes Bearing Hemilabile κ2-(C,S)?Thioether-Functionalized NHC Ligands: Application to Amide Synthesis from Alcohol and Amine
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Amide synthesis is one of the most crucial transformations in chemistry and biology. Among various catalytic systems, N-heterocyclic carbene (NHC)-based ruthenium (Ru) catalyst systems have been proven to be active for direct synthesis of amides by sustainable acceptorless dehydrogenative Coupling of primary alcohols with amines. Most often, these catalytic systems usually use monodentate NHC and thus require an additional ligand to obtain high reactivity and selectivity. In this work, a series of cationic Ru(II)(η6-p-cymene) complexes with thioether-functionalized N-heterocyclic carbene ligands (imidazole and benzimidazole-based) have been prepared and fully characterized. These complexes have then been used in the amidation reaction and the most promising one (i. e. 3 c) has been applied on a large range of substrates. High conversions albeit with moderate yields have generally been obtained.
- Achard, Thierry,Bellemin-Laponnaz, Stéphane,Chen, Weighang,Egly, Julien,Maisse-Fran?ois, Aline
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supporting information
(2022/01/20)
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- Nickel Complexes Bearing N,N,O-Tridentate Salicylaldiminato Ligand: Efficient Catalysts for Imines Formation via Dehydrogenative Coupling of Primary Alcohols with Amines
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Treatment of salicylaldiminato ligand L1H-L2H (L1H = 2,4-di-tert-butyl-6-((quinolin-8-ylimino)methyl)phenol; L2H = 2,4-di-tert-butyl-6-(((2-(diethylamino)ethyl)imino)methyl)phenol) with Ni(OAc)2·4H2O in refluxing ethanol afforded nickel complexes [(L1)Ni(OAc)] (1) and [(L2)Ni(OAc)] (2), respectively. Reaction of L3H (L3H = (2,4-di-tert-butyl-6-(((2-(pyridin-2-yl)ethyl)imino)methyl)phenol)) with Ni(OAc)2·4H2O in the presence of excess triethylanmine gave the dual ligands coordinated nickel complex [(L2)2Ni] (3). Complexes 1-3 were well characterized by high-resolution mass spectrometry, infrared spectroscopy, elemental analysis, and X-ray diffraction analysis. All the three Ni(II) complexes exhibited efficient activity and good selectivity in the acceptorless dehydrogenative coupling of alcohols and amines to produce imines and diimines. The present protocol provides an atom-economical and sustainable route for the synthesis of various imine derivatives by employing an earth-abundant nickel salt and easily prepared salicylaldiminato ligands.
- Han, Zhangang,Hao, Zhiqiang,Lin, Jin,Lu, Guo-Liang,Zhang, Junhua,Zhang, Xiaoying
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p. 3843 - 3853
(2021/11/18)
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- Enantioselective Reductive Cyanation and Phosphonylation of Secondary Amides by Iridium and Chiral Thiourea Sequential Catalysis
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The combination of transition-metal catalysis and organocatalysis increasingly offers chemists opportunities to realize diverse unprecedented chemical transformations. By combining iridium with chiral thiourea catalysis, direct enantioselective reductive cyanation and phosphonylation of secondary amides have been accomplished for the first time for the synthesis of enantioenriched chiral α-aminonitriles and α-aminophosphonates. The protocol is highly efficient and enantioselective, providing a novel route to the synthesis of optically active α-functionalized amines from the simple, readily available feedstocks. In addition, the reactions are scalable and the thiourea catalyst can be recycled and reused.
- Chen, Dong-Huang,Sun, Wei-Ting,Zhu, Cheng-Jie,Lu, Guang-Sheng,Wu, Dong-Ping,Wang, Ai-E,Huang, Pei-Qiang
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supporting information
p. 8827 - 8831
(2021/03/16)
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- Efficient Co-Catalyzed Double Hydroboration of Nitriles: Application to One-Pot Conversion of Nitriles to Aldimines
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The commercially available and bench-stable Co(acac)2/dpephos system is employed as a precatalyst for selective and efficient room temperature hydroboration of organic nitriles with HBPin to produce a series of N,N-diborylamines [RN(BPin)2], which react in situ with aldehydes to give aldimines. Formation of aldimines from N,N-diborylamines does not require a dehydrating agent, is applicable to a wide range of N,N-diborylamine and aldehyde substrates and is highly chemoselective, being unaffected by various common functional groups, such as alkenes, alkynes, secondary amines, ketones, esters, amides, carboxylic acids, pyridines, nitriles, and nitro compounds. The overall transformation represents a synthetically valuable approach to aldimines from nitriles and can be performed in a sequential one-pot manner, tolerating ester, lactone, carboxamide and unactivated alkene functionalities.
- Gudun, Kristina A.,Slamova, Ainur,Hayrapetyan, Davit,Khalimon, Andrey Y.
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supporting information
p. 4963 - 4968
(2020/04/17)
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- Electrochemical, Iodine-Mediated α-CH Amination of Ketones by Umpolung of Silyl Enol Ethers
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The electrochemical, oxidative Umpolung reaction of silyl enol ethers utilizing simple iodide salts for the synthesis of α-amino ketones is described. The products were isolated in excellent yields of up to 100percent, and various functionalized starting materials were accepted in an undivided electrochemical cell design. Moreover, a sensitivity assessment to ensure an improved reproducibility of the reaction and cyclic voltammetry experiments were performed to postulate a plausible reaction mechanism on their basis.
- Strehl, Julia,Hilt, Gerhard
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supporting information
p. 5968 - 5972
(2020/08/12)
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- Bi-functional catalyst of porous N-doped carbon with bimetallic FeCu for solvent-free resultant imines and hydrogenation of nitroarenes
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The efficient and stable catalyst applied to the transformation of amines into the corresponding imines and hydrogenation of nitroarenes under mild reaction conditions is reported. The catalytic performance of porous N-doped carbon with FeCu (FeCu@NPC) catalyst are tested by aromatic alcohol-based N-alkylated of amines with solvent-free and hydrogenation of nitroarenes via N2H4·H2O. The results proved that the yield of these two reactions are all over 99.9% under optimum condition. Moreover, the synergistic effect of the catalyst for N-alkylated reaction was investigated through the kinetic study. The catalyst can be easily separated from reaction system by an external magnetism, and can be recycled and reutilized for at least 4 runs with conversions are all over 75%. The study of the catalyst indicated that it was suitable for the reactions in industry. Hence, the catalysis process by the inexpensive metals-based catalyst is green and sustainable.
- Wang, Kaizhi,Gao, Wenbing,Jiang, Pengbo,Lan, Kai,Yang, Ming,Huang, Xiaokang,Ma, Lei,Niu, Fang,Li, Rong
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- Catalytic Assessment of Copper(I) Complexes and a Polymer Analog towards the One-Pot Synthesis of Imines and Quinoxalines
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Three copper(I) complexes, [CuCl(L)(PPh3)2] [L = FL (1), BL (2) or TL (3)] were prepared from [(PPh3)2Cu(μ-Cl)2Cu(PPh3)] and N-carbamothioylfuran-2-carboxamide (FL), N-carbamothioylbenzamide (BL) or N-carbamothioylthiophene-2-carboxamide (TL) ligands in benzene and four-coordinated tetrahedral copper complexes were well characterized by various spectroscopic techniques (UV/Vis, FT-IR, 1H NMR, 13C NMR and 31P NMR). The molecular structure of the ligands (FL and BL) and complexes was established from single-crystal X-ray diffraction studies. Copper complexes have been shown to catalyse the one-pot synthesis of imines and quinoxalines. Heterogenized catalyst (4) was prepared by reacting more active complex 3 with polystyrene supported triphenylphosphane, and characterized by elemental analyses, and DRS-UV, FT-IR, ICP-OES, and solid-state NMR techniques. Catalytic activity of the complexes (3 and 4) was tested in the formation of imines from alcohols and amines, and quinoxalines from hydroxy ketones and diamines. Heterogeneity and reusability of catalyst 4 were evaluated, and the catalyst can be reused for four runs without any loss in activity.
- Sindhuja, Dharmalingam,Vasanthakumar, Punitharaj,Bhuvanesh, Nattamai,Karvembu, Ramasamy
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p. 3588 - 3596
(2019/08/20)
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- Activation of primary amines by copper(i)-based lewis acid promoters in the solventless synthesis of secondary propargylamines
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Primary amines are activated by copper(I)-based Lewis acid promoters in an A 3 -coupling one-pot solventless reaction with aldehydes and phenylacetylene for the synthesis of secondary propargylamines. The reaction is promoted by a CuSO 4 /NaI system, a practical precursor of the in situ generated effective CuI/I 2 system, that worked well, but only in a restricted number of examples. Substitution of I 2 with CeCl 3 ·7H 2 O in a one-pot two-step reaction provided good yields and a wider applicability, with the added value given by a safer procedure.
- Cimarelli, Cristina,Navazio, Federica,Rossi, Federico V.,Del Bello, Fabio,Marcantoni, Enrico
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p. 2387 - 2396
(2019/05/27)
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- One-Pot Reductive Allylation of Amides by Using a Combination of Titanium Hydride and an Allylzinc Reagent: Application to a Total Synthesis of (-)-Castoramine
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A one-pot direct reductive allylation protocol has been developed for the synthesis of secondary amines by using titanium hydride and an allylzinc reagent. This protocol is applicable to a broad range of substrates, including acyclic amides, benzamides, α,β-unsaturated amides, and lactams. The stereochemical outcome obtained from the reaction with crotylzinc reagent suggested that the allylation reaction proceeds through a six-membered cyclic transition state. A total synthesis of (-)-castoramine was accomplished by following this protocol for the highly stereoselective construction of contiguous stereocenters.
- Itabashi, Suguru,Shimomura, Masashi,Sato, Manabu,Azuma, Hiroki,Okano, Kentaro,Sakata, Juri,Tokuyama, Hidetoshi
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supporting information
p. 1786 - 1790
(2018/07/03)
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- Mechanochemical lignin-mediated strecker reaction
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A mechanochemical Strecker reaction involving a wide range of aldehydes (aromatic, heteroaromatic and aliphatic), amines, and KCN afforded a library of α-aminonitriles upon mechanical activation. This multicomponent process was efficiently activated by li
- Dabral, Saumya,Turberg, Mathias,Wanninger, Andrea,Bolm, Carsten,Hernández, José G.
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- Dual Heterogeneous Catalyst Pd-Au@Mn(II)-MOF for One-Pot Tandem Synthesis of Imines from Alcohols and Amines
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A new Mn(II) metal-organic framework (MOF) 1 was synthesized by the combination of 4,4,4-trifluoro-1-(4-(pyridin-4-yl)phenyl)butane-1,3-dione (L) and Mn(OAc)2 in solution. 1 features a threefold-interpenetrating NbO net containing honeycomb-like channels, in which the opposite Mn(II)···Mn(II) distance is 23.5075(10) ?. Furthermore, 1 can be an ideal platform to support Pd-Au bimetallic alloy nanoparticles to generate a composite catalytic system of Pd-Au@Mn(II)-MOF (2). 2 can be a highly active bifunctional heterogeneous catalyst for the one-pot tandem synthesis of imines from benzyl alcohols and anilines and from benzyl alcohols and benzylamines.
- Chen, Gong-Jun,Ma, Hui-Chao,Xin, Wen-Ling,Li, Xiao-Bo,Jin, Fa-Zheng,Wang, Jing-Si,Liu, Ming-Yang,Dong, Yu-Bin
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p. 654 - 660
(2017/01/13)
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- Method for synthesizing imine through cross-coupling of hydroxylation phenanthroline copper complex/O2 catalytic oxidation alcohol and amine
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The invention discloses a method for synthesizing imine through cross-coupling of hydroxylation phenanthroline copper complex/O2 catalytic oxidation alcohol and amine. According to the method, an economical and cheap hydroxylation phenanthroline copper complex is selected as a catalyst, green O2 is selected as an oxidizing agent, cross-coupling of alcohol and amine is realized under the condition of normal temperature, alkali and an expensive free radical of nitroxide is prevented from being used, and a series of imine compounds are successfully prepared. The method provided by the invention is high in reaction selectivity and relatively wide in a substrate application range, and has a great industrial application potential.
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Paragraph 0017; 0026; 0027
(2017/12/02)
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- P-N Cooperative Borane Activation and Catalytic Hydroboration by a Distorted Phosphorous Triamide Platform
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Studies of the stoichiometric and catalytic reactivity of a geometrically constrained phosphorous triamide 1 with pinacolborane (HBpin) are reported. The addition of HBpin to phosphorous triamide 1 results in cleavage of the B-H bond of pinacolborane through addition across the electrophilic phosphorus and nucleophilic N-methylanilide sites in a cooperative fashion. The kinetics of this process of were investigated by NMR spectroscopy, with the determined overall second-order empirical rate law given by ν = -k[1][HBpin], where k = 4.76 × 10-5 M-1 s-1 at 25 °C. The B-H bond activation process produces P-hydrido-1,3,2-diazaphospholene intermediate 2, which exhibits hydridic reactivity capable of reacting with imines to give phosphorous triamide intermediates, as confirmed by independent synthesis. These phosphorous triamide intermediates are typically short lived, evolving with elimination of the N-borylamine product of imine hydroboration with regeneration of the deformed phosphorous triamide 1. The kinetics of this latter process are shown to be first-order, indicative of a unimolecular mechanism. Consequently, catalytic hydroboration of a variety of imine substrates can be realized with 1 as the catalyst and HBpin as the terminal reagent. A mechanistic proposal implicating a P-N cooperative mechanism for catalysis that incorporates the various independently verified stoichiometric steps is presented, and a comparison to related phosphorus-based systems is offered.
- Lin, Yi-Chun,Hatzakis, Emmanuel,McCarthy, Sean M.,Reichl, Kyle D.,Lai, Ting-Yi,Yennawar, Hemant P.,Radosevich, Alexander T.
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supporting information
p. 6008 - 6016
(2017/05/04)
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- Concise synthesis of spergualin-inspired molecules with broad-spectrum antibiotic activity
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There is a growing need to identify new, broad-spectrum antibiotics. The natural product spergualin was previously shown to have promising anti-bacterial activity and a privileged structure, but its challenging synthesis had limited further exploration. For example, syntheses of spergualin and its analogs have been reported in approximately 10 linear steps, with overall yields between 0.3 and 18%. Using the Ugi multi-component reaction, we assembled spergualin-inspired molecules in a single step, dramatically improving the overall yield (20% to 96%). Using this strategy, we generated 43 new analogs and tested them for anti-bacterial activity against two Gram-negative and four Gram-positive strains. We found that the most potent analogue, compound 6, had MIC values between 4 and 32 μg mL-1 against the six strains, which is a significant improvement on spergualin (MIC ~ 6.25 to 50 μg mL-1). These studies provide a concise route to a broad-spectrum antibiotic with a novel chemical scaffold. This journal is
- Assimon, Victoria A.,Shao, Hao,Garneau-Tsodikova, Sylvie,Gestwicki, Jason E.
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p. 912 - 918
(2015/05/27)
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- Synthesis of N-benzyl-N-phenylthiophene-2-carboxamide analogues as a novel class of enterovirus 71 inhibitors
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A series of novel human enterovirus 71 inhibitors, N-benzyl-N-phenylthiophene-2-carboxamide analogues, were synthesized and their antiviral activities were evaluated in vitro. Most derivatives of this structure against EV71 had a low micromolar range in the RD (rhabdomyosarcoma) cell lines. The most potent compound 5a, N-(4-bromobenzyl)-N-(4-fluorophenyl)thiophene-2-carboxamide, showed low micromolar activity against EV71 (EC50 = 1.42 μM) compared to the reference anti-EV71 drug enviroxime (EC50 = 0.15 μM). Preliminary SAR studies revealed that the thiophene-2-carboxamide core is crucial for maintaining antiviral activity, and N-substituent phenyl groups largely influenced the anti-EV71 efficacy of this new class of potent antiviral agents.
- Pan, Jiawei,Han, Xin,Sun, Ningyuan,Wu, Haoming,Lin, Dandan,Tien, Po,Zhou, Hai-Bing,Wu, Shuwen
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p. 55100 - 55108
(2015/07/07)
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- Discrete multiporphyrin pseudorotaxane assemblies from di- and tetravalent porphyrin building blocks
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Two pairs of divalent and tetravalent porphyrin building blocks carrying the complementary supramolecular crown ether/secondary ammonium ion binding motif have been synthesized and their derived pseudorotaxanes have been studied by a combination of NMR spectroscopy in solution and ESI mass spectrometry in the gas phase. By simple mixing of the components the formation of discrete dimeric and trimeric (metallo)porphyrin complexes predominates, in accordance to binding stoichiometry, while the amount of alternative structures can be neglected. Our results illustrate the power of multivalency to program the multicomponent self-assembly of specific entities into discrete functional nanostructures.
- Lohse, Mirko,Von Krbek, Larissa K. S.,Radunz, Sebastian,Moorthy, Suresh,Schalley, Christoph A.,Hecht, Stefan
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supporting information
p. 748 - 762
(2015/06/08)
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- Lanthanide coordination polymer constructed from 2,2′-bipyridyl-4,4′-dicarboxylic acid: Structure, catalysis and fluorescence
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Two new isostructural lanthanide coordination polymers (Ln-CPs) [Ln2(bpdc)3(DMF)2] (Ln = Tb for 1, Eu for 2) with two kinds of one-dimensional channels along the a axis, were synthesized by 2,2′-bipyridyl-4,4′-dicarboxylic acid (H2bpdc) under solvothermal conditions. With exposed Lewis acid Ln3+ centers, 1 as a heterogeneous catalyst shows good catalytic reactivity and selectivity for the Strecker reaction affording medium to excellent conversion yields. Luminescent studies illustrate that 1 and 2 show intensive green and red luminescence triggered by efficient antenna effect of ligands under UV light, respectively. Moreover, 1 exhibits sensitive fluorescent response to Cu2+ in DMF solution.
- Wang, Shengyan,Xu, Jianing,Zheng, Jifu,Chen, Xiaodong,Shan, Liang,Gao, Lijuan,Wang, Li,Yu, Miao,Fan, Yong
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supporting information
p. 81 - 86
(2015/09/15)
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- Expanding the utility of flow hydrogenation - A robust protocol restricting hydrodehalogenation
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A commonly observed limitation of conducting hydrogenations under flow chemistry conditions is hydrodehalogenation. In a bid to circumvent this limitation a series of hydrogenation catalysts were screened, with 5% Pt/C (sulfided) catalyst identified as an effective catalyst to selectively effect reductive aminations, nitro reduction, and alkene reductions in the presence of halogen atoms. Additionally the optimised protocol cleanly reduced imines in the presence of a furan moiety indicating potential amenability to other labile functionalities.
- Hizartzidis, Lacey,Cossar, Peter J.,Robertson, Mark J.,Simone, Michela I.,Young, Kelly A.,McCluskey, Adam,Gordon, Christopher P.
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p. 56743 - 56748
(2014/12/12)
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- Selective aerobic oxidation of alcohols to aldehydes, carboxylic acids, and imines catalyzed by a Ag-NHC complex
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Silver NHC catalysts have been developed for the selective oxidation of alcohols to aldehydes or carboxylic acids in the presence of BnMe3NOH or KOH under dry air. The aerobic oxidation conditions are mild, and the yield is excellent. Further tandem catalysis enables the one-pot synthesis of imines in excellent yield. Only 0.1 mol % of the catalyst is required.
- Han, Lei,Xing, Ping,Jiang, Biao
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supporting information
p. 3428 - 3431
(2014/07/21)
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- Direct synthesis of imines via solid state reactions of carbamates with aldehydes
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Various solid carbamates were prepared from the reactions of liquid amines with carbon dioxide in an autoclave and these carbamates were used as stable, efficient alternatives for toxic liquid amines. Solid-state grinding of carbamates and aldehydes, using a mortar and pestle, produced imines as the sole products in greater than 97% yields. Complete conversions were generally accomplished within a day at 25 °C without using solvents or additives. Reaction rates were drastically enhanced upon increasing the reaction temperature. In contrast, reactions of aldehydes with liquid amines in the presence of solvent or in neat conditions afforded imines in moderate yields along with by-products.
- Lee, Byeongno,Lee, Kyu Hyung,Lim, Byung Wook,Cho, Jaeheung,Nam, Wonwoo,Hur, Nam Hwi
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supporting information
p. 389 - 394
(2013/05/08)
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- General, green, and scalable synthesis of imines from alcohols and amines by a mild and efficient copper-catalyzed aerobic oxidative reaction in open air at room temperature
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A general, green, and scalable synthesis of the useful imines and a,b-unsaturated imines is successfully achieved by a low-loading and powerful, mild and efficient copper-catalyzed aerobic oxidative reaction of alcohols and amines in the open air at room temperature under base- and dehydrating reagent-free conditions. This practical reaction can use air as the economic and green oxidant, tolerates a wide range of substrates, can afford high yields of the target imines on a large scale, and produces water as the only by-product, and thus being the best imination method as yet using alcohols and amines directly.
- Tian, Haiwen,Yu, Xiaochun,Li, Qiang,Wang, Jianxin,Xu, Qing
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supporting information
p. 2671 - 2677,7
(2012/12/12)
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- Synthesis of α, α-dideutero-β-amino esters
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A straight forward entry to α, α-dideutero-β-amino esters starting from the corresponding imines and deuterated acetonitrile has been developed involving a two-step process.
- Chandrasekhar,Pendke, Mrunal,Muththe, Chandrashekar,Akondi, Srirama Murthy,Mainkar, Prathama S.
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experimental part
p. 1292 - 1295
(2012/03/27)
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- Highly efficient oxidation of amines to imines by singlet oxygen and its application in ugi-type reactions
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A variety of secondary benzylic amines were oxidized to imines in 90% to >99% yields by singlet oxygen generated from oxygen and a porphyrin photosensitizer. On the basis of these reactions, a protocol was developed for oxidative Ugi-type reactions with singlet oxygen as the oxidant. This protocol has been used to synthesize C1- and N-functionalized benzylic amines in up to 96% yields.
- Jiang, Gaoxl,Chen, Jian,Huang, Jie-Sheng,Che, Chi-Ming
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scheme or table
p. 4568 - 4571
(2009/12/07)
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- Indium-silver- and zinc-silver-mediated barbier-grignard-type alkylation reactions of imines by using unactivated alkyl halides in aqueous media
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In the presence of In or Zn/AgI/InCl3, an efficient and practical method for the Barbier-Grignard-type alkylation reactions of simple imines by using a one-pot condensation of various aldehydes, amines (including the aliphatic and chiral version), and secondary alkyl iodides has been developed. The reaction proceeded more efficiently in water than in organic solvents. Without the use of CuI, it mainly gave the imine self-reductive coupling product, which was not the alkylated product. Good diastereoselectivities (up to 92:8 dr) were obtained when L-valine methyl ester was used as the substrate.
- Shen, Zhi-Liang,Cheong, Hao-Lun,Loh, Teck-Peng
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experimental part
p. 1875 - 1880
(2009/04/06)
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- Synthesis of a natural product-inspired eight-membered ring lactam library via ring-closing metathesis
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We have prepared a novel speculative eight-membered lactam demonstration library based on the skeletal structure of the potent antitumor marine natural product octalactin A. The basic scaffold was readily constructed in a convergent fashion via ring-closing metathesis chemistry from the corresponding diene amides. A cursory examination of the biological properties of the library validates the relevance and significance of these structures.
- Brown, Neil,Xie, Baohan,Markina, Nataliya,VanderVelde, David,Perchellet, Jean-Pierre H.,Perchellet, Elisabeth M.,Crow, Kyle R.,Buszek, Keith R.
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scheme or table
p. 4876 - 4879
(2009/05/30)
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- Synthetic and mechanistic studies of indium-mediated allylation of imines in ionic liquids
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(Chemical Equation Presented) Aldimines derived from aryl and non-enolizable aliphatic aldehydes were allylated with allyl bromide mediated by indium powder in [bpy][BF4] (bpy = N-butylpyridine) to give good yields of the corresponding homoallylic amines. Selective formation of monoallylated amines can be achieved by varying the amount of bromide ion additive in the form of [bpy][Br]. The transient organoindium intermediates, allylindium-(I) and allylindium(III) dibromide formed in the reaction, were studied by NMR spectroscopy to explain the selectivity.
- Man, Chun Law,Tin, Wai Cheung,Wong, Kwok-Yin,Tak, Hang Chan
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p. 923 - 929
(2007/10/03)
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- A molecular plug - socket connector
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A monocationic plug-socket connector that is composed, at the molecular level, of three components, (1) a secondary dialkylammonium center (CH 2NH2+CH2), which can play the role of a plug toward dibenzo[24]crown-8 (DB24C8), (2) a rigid and conducting biphenyl spacer, and (3) 1,4-benzo-1,5-naphtho[36]crown-10 (BN36C10), capable of playing the role of a socket toward a 4,4′-bipyridinium dicationic plug, was synthesized and displays the ability to act as a plug-socket connector. The fluorescent signal changes associated with the 1,5-dioxynaphthalene unit of its BN36C10 portion were monitored to investigate the association of this plug-socket connector with the complementary socket and plug compounds. The results indicate that (1) the CH2NH2+CH 2 part of the molecular connector can thread DB24C8 in a trivial manner and (2) the BN36C10 ring of the connector can be threaded by a 1,1′-dioctyl-4,4′-bipyridinium ion only after the CH 2NH2+CH2 site is occupied by a DB24C8 ring. The two connections of the three-component assembly are shown to be controlled reversibly by acid/base and red/ox external inputs, respectively. The results obtained represent a key step for the design and construction of a self-assembling supramolecular system in which the molecular electron source can be connected to the molecular electron drain by a molecular elongation cable.
- Rogez, Guillaume,Ribera, Belen Ferrer,Credi, Alberto,Ballardini, Roberto,Gandolfi, Maria Teresa,Balzani, Vincenzo,Liu, Yi,Northrop, Brian H.,Stoddart, J. Fraser
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p. 4633 - 4642
(2007/10/03)
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- New reactions of IBX: Oxidation of nitrogen- and sulfur-containing substrates to afford useful synthetic intermediates
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New reactions for the synthetic toolbox: 2-lodoxybenzoic acid (IBX) was employed to access a diverse array of useful synthetic intermediates. Among other transformations, the developed chemistry converts amines into imines, dithianes into carbonyl groups, N-heterocycles into N-heteroaromatic compounds, and hydroxylamines into oximes in high yields.
- Nicolaou,Mathison, Casey J. N.,Montagnon, Tamsyn
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p. 4077 - 4082
(2007/10/03)
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