- Copper-catalyzed enantioselective alkene carboetherification for the synthesis of saturated six-membered cyclic ethers
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The enantioselective copper-catalyzed oxidative coupling of alkenols with styrenes for the construction of dihydropyrans, isochromans, pyrans and morpholines is reported. A concise formal synthesis of a σ1receptor ligand using this alkene carbo
- Berhane, Ilyas A.,Burde, Ameya S.,Chemler, Sherry R.,Kennedy-Ellis, Jonathan J.,Zurek, Eva
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supporting information
p. 10099 - 10102
(2021/10/06)
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- Copper-Catalyzed Enantioselective Hydroalkoxylation of Alkenols for the Synthesis of Cyclic Ethers
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The copper-catalyzed enantioselective intramolecular hydroalkoxylation of unactivated alkenes for the synthesis of tetrahydrofurans, phthalans, isochromans, and morpholines from 4- and 5-alkenols is reported. The substrate scope is complementary to existing enantioselective alkene hydroalkoxylations and is broad with respect to substrate backbone and alkene substitution. The asymmetric induction and isotopic labeling studies support a polar/radical mechanism involving enantioselective oxycupration followed by C-[Cu] homolysis and hydrogen atom transfer. Synthesis of the antifungal insecticide furametpyr was accomplished.
- Chen, Dake,Berhane, Ilyas A.,Chemler, Sherry R.
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supporting information
p. 7409 - 7414
(2020/06/29)
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- Synthesis of Tetrahydroisoquinolines through an Iron-Catalyzed Cascade: Tandem Alcohol Substitution and Hydroamination
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Rapid assembly of saturated nitrogen heterocycles - the synthetically more challenging variants of their aromatic relatives - can expedite the synthesis of biologically relevant molecules. Starting from a benzylic alcohol tethered to an unactivated alkene, an iron-catalyzed tandem alcohol substitution and hydroamination provides access to tetrahydroisoquinolines in a single synthetic step. Using a mild iron-based catalyst, the combination of these operations forms two carbon-nitrogen bonds and provides a unique annulation strategy to access this valuable core.
- Marcyk, Paul T.,Cook, Silas P.
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supporting information
p. 6741 - 6744
(2019/09/07)
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- Carbonylative Coupling of Alkyl Zinc Reagents with Benzyl Bromides Catalyzed by a Nickel/NN2 Pincer Ligand Complex
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An efficient catalytic protocol for the three-component assembly of benzyl bromides, carbon monoxide, and alkyl zinc reagents to give benzyl alkyl ketones is described, and represents the first nickel-catalyzed carbonylative coupling of two sp3-carbon fragments. The method, which relies on the application of nickel complexed with an NN2-type pincer ligand and a controlled release of CO gas from a solid precursor, works well with a range of benzylic bromides. Mechanistic studies suggest the intermediacy of carbon-centered radicals.
- Andersen, Thomas L.,Donslund, Aske S.,Neumann, Karoline T.,Skrydstrup, Troels
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supporting information
p. 800 - 804
(2017/12/26)
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- Indium Catalyzed Hydrofunctionalization of Styrene Derivatives Bearing a Hydroxy Group with Organosilicon Nucleophiles
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Hydrofunctionalization is one of the most important transformation reactions of alkenes. Herein, we describe the development of an indium-triiodide-catalyzed hydrofunctionalization of alkenes bearing a hydroxy group using various types of organosilicon nucleophiles. Indium triiodide was the most effective catalyst, whereas typical Lewis acids such as TiCl4, AlCl3, and BF3·OEt2 were ineffective. Many functional groups were successfully introduced, and these resulted in yields of 31-86%. Various styrene derivatives were also applicable to this reaction. Mechanistic investigation revealed that the present hydrofunctionalization proceeded through Br?nsted acid-catalyzed intramolecular hydroalkoxylation of alkenes followed by InI3-catalyzed substitution reaction of cyclic ether intermediates.
- Kita, Yuji,Yata, Tetsuji,Nishimoto, Yoshihiro,Yasuda, Makoto
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p. 740 - 753
(2018/01/28)
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- Macrocyclic Modulators of the Ghrelin Receptor
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The present invention provides novel conformationally-defined macrocyclic compounds that have been demonstrated to be selective modulators of the ghrelin receptor (growth hormone secretagogue receptor, GHS-R1a and subtypes, isoforms and variants thereof). Methods of synthesizing the novel compounds are also described herein. These compounds are useful as agonists of the ghrelin receptor and as medicaments for treatment and prevention of a range of medical conditions including, but not limited to, metabolic and/or endocrine disorders, gastrointestinal disorders, cardiovascular disorders, obesity and obesity-associated disorders, central nervous system disorders, genetic disorders, hyperproliferative disorders and inflammatory disorders.
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- Tuning the Diiron Core Geometry in Carboxylate-Bridged Macrocyclic Model Complexes Affects Their Redox Properties and Supports Oxidation Chemistry
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We introduce a novel platform to mimic the coordination environment of carboxylate-bridged diiron proteins by tethering a small, dangling internal carboxylate, (CH2)nCOOH, to phenol-imine macrocyclic ligands (H3PIMICn). In the presence of an external bulky carboxylic acid (RCO2H), the ligands react with [Fe2(Mes)4] (Mes = 2,4,6-trimethylphenyl) to afford dinuclear [Fe2(PIMICn)(RCO2)(MeCN)] (n = 4-6) complexes. X-ray diffraction studies revealed structural similarities between these complexes and the reduced diiron active sites of proteins such as Class I ribonucleotide reductase (RNR) R2 and soluble methane monooxygenase hydroxylase. The number of CH2 units of the internal carboxylate arm controls the diiron core geometry, affecting in turn the anodic peak potential of the complexes. As functional synthetic models, these complexes facilitate the oxidation of C-H bonds in the presence of peroxides and oxo transfer from O2 to an internal phosphine moiety.
- Wang, Fang,Becker, Sabine,Minier, Mikael A.,Loas, Andrei,Jackson, Megan N.,Lippard, Stephen J.
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supporting information
p. 11050 - 11058
(2017/09/26)
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- One-Pot Trimetallic Relay Catalysis: A Unified Approach for the Synthesis of β-Carbolines and Other [c]-Fused Pyridines
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A divergent strategy is presented for the synthesis of 1,3-di- and 1,3,4-trisubstituted β-carbolines through an unprecedented one-pot triple-orthogonal-metal relay catalysis, and 1,3-disubstituted 4-hydroxy-β-carbolines through a one-pot bimetallic relay
- Dhiman, Seema,Mishra, Uttam K.,Ramasastry
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supporting information
p. 7737 - 7741
(2016/07/07)
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- Nickel(0)-catalyzed intramolecular reductive coupling of alkenes and aldehydes or ketones with hydrosilanes
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A nickel(0)-catalyzed reductive coupling of aldehydes and simple alkenes with hydrosilanes has been developed. A variety of silyl-protected 1-indanol derivatives were prepared in a highly diastereoselective manner (up to >99:1 dr) by employing a combination of nickel(0)/N-heterocyclic carbene and triethylsilane. The present system was also applied to a reductive coupling with ketones. Preliminary results of a nickel(0)-catalyzed asymmetric three-component coupling reaction of an aldehyde, an alkene, and triethylsilane are also shown.
- Hayashi, Yukari,Hoshimoto, Yoichi,Kumar, Ravindra,Ohashi, Masato,Ogoshi, Sensuke
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supporting information
p. 6237 - 6240
(2016/05/19)
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- Spiro(imidazo[1,2-a]pyrano[2,3-c]pyridine-9-indenes) as inhibitors of gastric acid secretion
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Asymmetric and symmetric spiro(imidazo[1,2-a]pyrano[2,3-c]pyridine-9-indenes) were prepared using a synthetic approach that comprised a cross-metathesis reaction and an acid-catalyzed cycloisomerisation as key steps. The target compounds constitute potent inhibitors of the gastric proton pump enzyme with inhibitory activity comparable to potassium-competitive acid blockers (P-CABs) belonging to the known 9-aryl-7H-8,9-dihydropyrano[2,3-c]imidazo[1,2-a]pyridine series. Spiro(imidazo[1,2-a]pyrano[2,3-c]pyridine-9,2′-indenes) represent the first example for P-CABs, in which the distance between the heterocyclic scaffold and the aryl residue has been modified, and are promising candidates for further development as anti-ulcer drugs.
- Palmer, Andreas Marc,Chrismann, Sandra,Muench, Gabriela,Brehm, Christof,Zimmermann, Peter Jan,Buhr, Wilm,Senn-Bilfinger, Joerg,Feth, Martin Philipp,Simon, Wolfgang Alexander
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experimental part
p. 368 - 384
(2011/02/26)
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- Discovery of a new class of macrocyclic antagonists to the human motilin receptor
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A novel class of macrocyclic peptidomimetics was identified and optimized as potent antagonists to the human motilin receptor (hMOT-R). Well-defined structure-activity relationships allowed for rapid optimization of potency that eventually led to high aff
- Marsault, Eric,Hoveyda, Hamid R.,Peterson, Mark L.,Saint-Louis, Carl,Landry, Annick,Vézina, Martin,Quellet, Luc,Wang, Zhigang,Ramaseshan, Mahesh,Beaubien, Sylvie,Benakli, Kamel,Beauchemin, Sophie,Déziel, Robert,Peeters, Théo,Fraser, Graeme L.
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p. 7190 - 7197
(2007/10/03)
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- Cyclization of aryl acyl radicals generated from S-(4-cyano)phenyl thiolesters by a nickel complex catalyzed electroreduction
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Aromatic acyl radicals generated from S-(4-cyano)phenyl 2-alkenylthiobenzoate by a nickel complex catalyzed electroreduction undergo 5- and 6-exo cyclization to give 1-indanone and dihydro-1-naphthalenone derivatives, respectively.
- Ozaki, Shigeko,Adachi, Masashi,Sekiya, Sayaka,Kamikawa, Rie
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p. 4586 - 4589
(2007/10/03)
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- Photolytic Reactions of (o-Allylbenzyl)dicarbonyl(η5-cyclopentadienyl)iron
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Photolysis of (o-allylbenzyl)dicarbonyl(η5-cyclopentadienyl)iron (4) at 20 deg C in CH2Cl2 leads to carbon-monoxide loss followed by intramolecular complexation to 2-(o-allylbenzyl)>carbonyl(η5-cyclopentadienyl)iron (13).At 50 deg C in C6D6, a photochemical rearrangement proceeds forming carbonyl (η5-cyclopentadienyl)3->iron (17).Depending on the temperature, photolysis of 4 leads to intermolecular reactions at the benzylic or allylic position of the ? complexes 13 and 17, respectively.
- Thoma, Gebhard,Giese, Bernd
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p. 1123 - 1129
(2007/10/02)
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- Palladium-catalyzed carbonylative cyclization via trapping of acylpalladium derivatives with internal enolates. Its scope and factors affecting the C-to-O ratio
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The Pd-catalyzed carbonylative cyclization reaction involving ω-acyl-substituted acylpalladium derivatives can proceed via intramolecular trapping with either C- or O-enolates; the preferential formation of either 5- or 6-membered rings dictates the C-to-
- Negishi, El-Ichi,Coperet, Christophe,Sugihara, Takumichi,Shimoyama, Izumi,Zhang, Yantao,Wu, Guangzhong,Tour, James M.
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p. 425 - 436
(2007/10/02)
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