- One-Pot Synthesis of α-Ketoamides from α-Keto Acids and Amines Using Ynamides as Coupling Reagents
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A one-pot strategy for α-keto amide bond formation have been developed by using ynamides as coupling reagents under extremely mild reaction conditions. Diversely structural α-ketoamides were afforded in up to 98% yield for 36 examples. This reaction features advantages such as practical coupling procedure, wide functional group tolerance, and extremely mild conditions and has potential applications in synthetic and medicinal chemistry.
- Ma, Jianting,Cui, Xue,Xu, Junyu,Tan, Yinfeng,Wang, Yan,Wang, Xuesong,Li, Youbin
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supporting information
p. 3661 - 3667
(2022/02/07)
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- Studies on gold(i) and gold(iii) alcohol functionalised NHC complexes
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Five pairs of novel chiral alcohol functionalised gold(i) and gold(iii) NHC complexes derived from chiral amino alcohols, were synthesized and characterised (NMR, IR, HRMS). Single crystal X-ray diffraction data of gold(i) and gold(iii) complexes are reported and discussed. The chiral imidazolium preligands were readily synthesizedviathe oxalamides, subsequent reduction and final orthoformate condensation. An improved method was used for generation of gold(i) NHC complexes (up to 92%) and further oxidation afforded the corresponding gold(iii) NHC complexes (up to 99%). All the Au(i) and Au(iii) NHC complexes proved far more catalytically active in a 1,6-enyne alkoxycyclization test reaction than our previously testedN,N- andP,N-ligated Au(iii) complexes. Comparative gold(i) and gold(iii) catalytic studies demonstrated different catalytic ability, depending on the NHC ligand flexibility and bulkiness. Excellent yields (92-99%) of target alkoxycyclization product were obtained with both gold(i) and gold(iii) complexes with the bulkyN1-Mes-N2-ethanol based NHC ligand.
- Jónsson, Helgi Freyr,Orthaber, Andreas,Fiksdahl, Anne
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p. 5128 - 5138
(2021/04/26)
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- Supporting-Electrolyte-Free Anodic Oxidation of Oxamic Acids into Isocyanates: An Expedient Way to Access Ureas, Carbamates, and Thiocarbamates
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We report a new electrochemical supporting-electrolyte-free method for synthesizing ureas, carbamates, and thiocarbamates via the oxidation of oxamic acids. This simple, practical, and phosgene-free route includes the generation of an isocyanate intermediate in situ via anodic decarboxylation of an oxamic acid in the presence of an organic base, followed by the one-pot addition of suitable nucleophiles to afford the corresponding ureas, carbamates, and thiocarbamates. This procedure is applicable to different amines, alcohols, and thiols. Furthermore, when single-pass continuous electrochemical flow conditions were used and this reaction was run in a carbon graphite Cgr/Cgr flow cell, urea compounds could be obtained in high yields within a residence time of 6 min, unlocking access to substrates that were inaccessible under batch conditions while being easily scalable.
- Petti, Alessia,Fagnan, Corentin,van Melis, Carlo G. W.,Tanbouza, Nour,Garcia, Anthony D.,Mastrodonato, Andrea,Leech, Matthew C.,Goodall, Iain C. A.,Dobbs, Adrian P.,Ollevier, Thierry,Lam, Kevin
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supporting information
p. 2614 - 2621
(2021/06/27)
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- Analogues of the Herbicide, N-Hydroxy- N-isopropyloxamate, Inhibit Mycobacterium tuberculosis Ketol-Acid Reductoisomerase and Their Prodrugs Are Promising Anti-TB Drug Leads
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New drugs to treat tuberculosis (TB) are urgently needed to combat the increase in resistance observed among the current first-line and second-line treatments. Here, we propose ketol-acid reductoisomerase (KARI) as a target for anti-TB drug discovery. Twenty-two analogues of IpOHA, an inhibitor of plant KARI, were evaluated as antimycobacterial agents. The strongest inhibitor of Mycobacterium tuberculosis (Mt) KARI has a Ki value of 19.7 nM, fivefold more potent than IpOHA (Ki = 97.7 nM). This and four other potent analogues are slow- and tight-binding inhibitors of MtKARI. Three compounds were cocrystallized with Staphylococcus aureus KARI and yielded crystals that diffracted to 1.6-2.0 ? resolution. Prodrugs of these compounds possess antimycobacterial activity against H37Rv, a virulent strain of human TB, with the most active compound having an MIC90 of 2.32 ± 0.04 μM. This compound demonstrates a very favorable selectivity window and represents a highly promising lead as an anti-TB agent.
- Kandale, Ajit,Patel, Khushboo,Hussein, Waleed M.,Wun, Shun Jie,Zheng, Shan,Tan, Lendl,West, Nicholas P.,Schenk, Gerhard,Guddat, Luke W.,McGeary, Ross P.
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p. 1670 - 1684
(2021/02/27)
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- Metal-, Photocatalyst-, and Light-Free Direct C-H Acylation and Carbamoylation of Heterocycles
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Direct C-H acylations and carbamoylations of heterocycles can now be readily achieved without requiring any conventional metal, photocatalyst, electrocatalysis, or light activation, thus significantly improving on sustainability, costs, toxicity, waste, and simplicity of the operational procedure. These mild conditions are also suitable for gram-scale reactions and late-stage functionalizations of complex molecules, including pharmaceuticals, N,N-ligands, and light-sensitive molecules.
- Westwood, Matthew T.,Lamb, Claire J. C.,Sutherland, Daniel R.,Lee, Ai-Lan
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supporting information
p. 7119 - 7123
(2019/09/03)
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- Design, Synthesis, and Evaluation of the Highly Selective and Potent G-Protein-Coupled Receptor Kinase 2 (GRK2) Inhibitor for the Potential Treatment of Heart Failure
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A novel class of therapeutic drug candidates for heart failure, highly potent and selective GRK2 inhibitors, exhibit potentiation of β-adrenergic signaling in vitro studies. Hydrazone derivative 5 and 1,2,4-triazole derivative 24a were identified as hit compounds by HTS. New scaffold generation and SAR studies of all parts resulted in a 4-methyl-1,2,4-triazole derivative with an N-benzylcarboxamide moiety with highly potent activity toward GRK2 and selectivity over other kinases. In terms of subtype selectivity, these compounds showed enough selectivity against GRK1, 5, 6, and 7 with almost equipotent inhibition to GRK3. Our medicinal chemistry efforts led to the discovery of 115h (GRK2 IC50 = 18 nM), which was obtained the cocrystal structure with human GRK2 and an inhibitor of GRK2 that potentiates β-adrenergic receptor (βAR)-mediated cAMP accumulation and prevents internalization of βARs in β2AR-expressing HEK293 cells treated with isoproterenol. Therefore, 115h appears to be a novel class of therapeutic for heart failure treatment.
- Okawa, Tomohiro,Aramaki, Yoshio,Yamamoto, Mitsuo,Kobayashi, Toshitake,Fukumoto, Shoji,Toyoda, Yukio,Henta, Tsutomu,Hata, Akito,Ikeda, Shota,Kaneko, Manami,Hoffman, Isaac D.,Sang, Bi-Ching,Zou, Hua,Kawamoto, Tetsuji
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p. 6942 - 6990
(2017/09/07)
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- The formation of CuCl2-specific metallogels of pyridyloxalamide derivatives in alcohols
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Isomeric pyridyloxalamide derivatives 1-3, which differed in the position of the nitrogen atom on the pyridyl ring, showed remarkably different gel-forming aptitudes in the presence of CuCl2 salt in alcohols. Whilst derivatives 1 and 3 formed a soluble complex and a solid precipitate, respectively, ligand 2 generated a remarkably metal- and anion-specific metallogel. Copyright
- Dzolic, Zoran,Cametti, Massimo,Milic, Dalibor,Zinic, Mladen
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supporting information
p. 5411 - 5416
(2013/06/05)
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- Practical synthesis of functionalized 1,5-disubstituted 1,2,4-triazole derivatives
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A general approach for the synthesis of 1,5-disubstituted-1,2,4-triazole compounds is described. A series of new oxamide-derived amidine reagents can be accessed in excellent yield with minimal purification necessary. Typically, these amidine reagents are stable crystalline solids and in certain cases were found to exist in a cyclic form as determined by NMR spectroscopy. Under optimized conditions, the direct reaction of these prepared reagents with various hydrazine hydrochloride salts efficiently generates the target triazoles. Both aromatic and aliphatic hydrazines react readily with the amidine reagents under very mild reaction conditions, delivering desired 1,5-disubstituted-1,2,4-triazole derivatives in good yields.
- Xu, Yingju,McLaughlin, Mark,Bolton, Emily N.,Reamer, Robert A.
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supporting information; experimental part
p. 8666 - 8669
(2011/02/28)
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- Synthesis and first X-ray structures of cobalt(II) and cobalt(III) complexes bearing 2,4-dioxo-alkanoic acid dialkylamide ligands
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The aerobic oxidation of 5-hydroxy pentenes to trans-tetrahydrofurans (THFs), the Mukaiyama oxidation, has in recent years emerged as a powerful tool in synthetic chemistry. In this report we describe the first crystal structures of 2,4-dioxo-alkanoic acid dialkylamide complexes for both Co(II) and Co(III) salts. The Co(II) structures show an unprecedented arrangement of atoms, with a central Co(II)(H2O)6 flanked by two Co(II) atoms each coordinated with three anionic chelating ligands. The dimeric Co(III) structures show two anionic chelating ligands and bridging hydroxyl groups.
- Wang, Jian,Morra, Nicholas A.,Zhao, Hongda,Gorman, Jeffrey S.T.,Lynch, Vincent,McDonald, Robert,Reichwein, John F.,Pagenkopf, Brian L.
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experimental part
p. 328 - 334
(2009/10/24)
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- Inhibitors of hepatitis C virus NS3·4A protease. Effect of P4 capping groups on inhibitory potency and pharmacokinetics
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Reversible tetrapeptide-based compounds have been shown to effectively inhibit the hepatitis C virus NS3·4A protease. Inhibition of viral replicon RNA production in Huh-7 cells has also been demonstrated. We show herein that the inclusion of hydrogen bond donors on the P4 capping group of tetrapeptide-based inhibitors result in increased binding potency to the NS3·4A protease. The capping groups also impart significant effects on the pharmacokinetic profile of these inhibitors.
- Perni, Robert B.,Chandorkar, Gurudatt,Cottrell, Kevin M.,Gates, Cynthia A.,Lin, Chao,Lin, Kai,Luong, Yu-Ping,Maxwell, John P.,Murcko, Mark A.,Pitlik, Janos,Rao, Govinda,Schairer, Wayne C.,Drie, John Van,Wei, Yunyi
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p. 3406 - 3411
(2008/02/08)
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- Synthesis and crystallographic characterization of chiral bis-oxazoline-amides. Fine-tunable ligands for Pd-catalyzed asymmetric alkylations
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New chiral chelating C2 bis-oxazoline-amide ligands (1) exhibiting a highly flexible molecular structure have been prepared in high yield through a versatile synthetic pathway. Combined crystallographic, variable temperature (VT)-NMR, IR, and ESI-MS studies have been carried out to investigate the nature of the 1-Pd complexes that are effective tools in controlling the stereochemical outcome of Pd-catalyzed allylic alkylations (ee up to 98%).
- Albano, Vincenzo Giulio,Bandini, Marco,Monari, Magda,Marcucci, Eleonora,Piccinelli, Fabio,Umani-Ronchi, Achille
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p. 6451 - 6458
(2007/10/03)
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- Design and synthesis of new bidentate alkoxy-NHC ligands for enantioselective copper-catalyzed conjugate addition
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A new family of chiral alkoxy-N-heterocyclic carbene (NHC) ligands has been designed for the enantioselective copper-catalyzed conjugate addition of dialkylzincs to enones. These new bidentate NHC ligands were synthesized in high overall yields using a five-step procedure starting from commercially available β-aminoalcohols. Influence of the temperature, base, solvent and copper source were studied in order to optimize the stereoselectivity of the addition. High reactivity and excellent enantioselectivity were obtained at ambient temperature with a range of cyclic enones and dialkylzinc. Addition to acyclic enones has also been studied.
- Clavier, Hervé,Coutable, Ludovic,Toupet, Lo?c,Guillemin, Jean-Claude,Mauduit, Marc
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p. 5237 - 5254
(2007/10/03)
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- Novel acyclic ligands. 3. The syntheses of some amino amides derived from amino acids
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The syntheses of variously protected amino amides derived from the reaction of oxalic esters with ethylenediamine and with the amino acids glycine, L-valine, and L-lysine are described in this paper. The products are potential contrast agents in magnetic resonance imaging (MRI).
- Elsworth, John F.,Msimang, Lorenzo N.,Jackson, Graham E.
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- Nonpeptide angiotensin II antagonists derived from 4H-1,2,4-triazoles and 3H-imidazo[1,2-b][1,2,4]triazoles
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By a variety of synthetic routes, we have synthesized a series of 3,4,5- trisubstituted 4H-1,2,4-triazoles and a related series of 3H-imidazo[1,2- b][1,2,4]triazoles and evaluated them in vitro and in vivo as angiotensin II (AII) antagonists. Principal efforts focused on triazoles bearing an n-alkyl substituent at C3 and a 4-[(2-carboxybenzoyl)amino]benzyl, (2'- carboxybiphenyl-4-yl)methyl, or [2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl side chain at N4. Among numerous variations at C5, benzylthio groups gave the best potency. Particularly noteworthy was 3-n-butyl-5-[(2- carboxybenzyl)thio]-4-[[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]-4H-1,2,4- triazole (71, IC50 1.4 nM), which blocked the AII pressor response in conscious rats at 0.3 mg/kg iv with a duration of action of approximately 6 h, similar to that of DuP 753. Although 71 was active orally only at a 10- fold higher dose level, good oral bioavailability was demonstrated for a monoacidic analogue 62. Most potent among the bicyclic derivatives was 2-n- butyl-5,6-dimethyl-3-[[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]-3H- imidazo[1,2-b][1,2,4]triazole (93, IC50 7.8 nM). The effects of hydrophobic, hydrogen-bonding, and ionic interactions with the AT1 receptor are considered.
- Ashton,Cantone,Chang,Hutchins,Strelitz,MacCoss,Chang,Lotti,Faust,Chen,Bunting,Schorn,Kivlighn,Siegl
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p. 591 - 609
(2007/10/02)
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- Synthesis of 1,3-Disubstituted Diazolidines
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Symmetrical and unsymmetrical 1,3-diaminoethanes 1 are obtained by the reduction of N,N'-disubstituted oxamides 4 with lithium aluminum hydride.The oxamides 4 are readily produced by treatment of diethyl oxalate with primary amines.The 1,3-diaminoethanes 1 lead to 1,3-diazolidines 2 on treatment with formaldehyde.
- Lambert, Joseph B.,Huseland, Dave E.,Wang, Gen-tai
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p. 657 - 658
(2007/10/02)
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- Antisecretory oxamic acid esters
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Variously substituted oxanilic acid esters possessing anti-secretary activity are useful anti-ulcer agents.
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