- Nickel-Catalyzed Reductive Cross-Coupling of Benzylic Sulfonium Salts with Aryl Iodides
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A nickel-catalyzed cross-electrophile coupling of benzylic sulfonium salts with aryl iodides has been developed, providing direct access to diarylalkanes from readily available and stable coupling partners. Preliminary mechanistic studies suggest that the C-S bond cleavage proceeds through a single-electron transfer process to generate a benzylic radical.
- Wang, Wei,Yao, Ken,Wu, Fan
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p. 361 - 366
(2022/03/07)
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- Aromatization as an Impetus to Harness Ketones for Metallaphotoredox-Catalyzed Benzoylation/Benzylation of (Hetero)arenes
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Herein we report ketones as feedstock materials in radical cross-coupling reactions under Ni/photoredox dual catalysis. In this approach, simple condensation first converts ketones into prearomatic intermediates that then act as activated radical sources for cross-coupling with aryl halides. Our strategy enables the direct benzylation/benzoylation of (hetero)arenes under mild reaction conditions with high functional group tolerance.
- Lee, Shao-Chi,Li, Li-Yun,Tsai, Zong-Nan,Lee, Yi-Hsin,Tsao, Yong-Ting,Huang, Pin-Gong,Cheng, Cheng-Ku,Lin, Heng-Bo,Chen, Ting-Wei,Yang, Chung-Hsin,Chiu, Cheng-Chau,Liao, Hsuan-Hung
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-
- Nickel-Catalyzed Electrochemical C(sp3)?C(sp2) Cross-Coupling Reactions of Benzyl Trifluoroborate and Organic Halides**
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Reported here is the redox neutral electrochemical C(sp2)?C(sp3) cross-coupling reaction of bench-stable aryl halides or β-bromostyrene (electrophiles) and benzylic trifluoroborates (nucleophiles) using nonprecious, bench-stable NiCl2?glyme/polypyridine catalysts in an undivided cell configuration under ambient conditions. The broad reaction scope and good yields of the Ni-catalyzed electrochemical coupling reactions were confirmed by 50 examples of aryl/β-styrenyl chloride/bromide and benzylic trifluoroborates. Potential applications were demonstrated by electrosynthesis and late-stage functionalization of pharmaceuticals and natural amino acid modification, and three reactions were run on gram-scale in a flow-cell electrolyzer. The electrochemical C?C cross-coupling reactions proceed through an unconventional radical transmetalation mechanism. This method is highly productive and expected to find wide-spread applications in organic synthesis.
- Luo, Jian,Hu, Bo,Wu, Wenda,Hu, Maowei,Liu, T. Leo
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p. 6107 - 6116
(2021/02/01)
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- Photoredox Heterobimetallic Dual Catalysis Using Engineered Covalent Organic Frameworks
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The functionalization of an imine-based layered covalent organic framework (COF), containing phenanthroline units as ligands, has allowed the obtention of a heterobimetallated material. Photoactive Ir and Ni fragments were immobilized within the porous structure of the COF, enabling heterogeneous light-mediated Csp3-Csp2cross-couplings. As radical precursors, potassium benzyl- and alkoxy-trifluoroborates, organic silicates, and proline derivatives were employed, which brings out the good versatility ofIr,Ni@Phen-COF. Moreover, in all the studied cases, an enhanced activity and stability have been observed in comparison with analogous homogenous systems.
- Alemán, José,Imaz, Inhar,López-Magano, Alberto,Mas-Ballesté, Rubén,Maspoch, Daniel,Ortín-Rubio, Borja
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p. 12344 - 12354
(2021/10/12)
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- Desulfurative Ni-Catalyzed Reductive Cross-Coupling of Benzyl Mercaptans/Mercaptoacetates with Aryl Halides
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The C-S activation and sulfur removal from native thiols is challenging, which limits their application as feedstock materials in organic synthesis despite their natural abundance. Herein, we introduce a per-/polyfluoroaryl moiety, which serves as a redox-active scaffold, into sp3-hybridized thiols to activate the C-S bond. Using a Ni catalyst with MgBr2 as an additive, the S group can be removed to yield an aliphatic radical that can react with an aryl halide in a reductive cross-coupling.
- Chan, Cheng-Lin,Hsu, Che-Ming,Lee, Shao-Chi,Li, Li-Yun,Liao, Hsuan-Hung,Mi?oza, Shinje,Tsai, Hao-En,Tsai, Zong-Nan,Tsao, Yong-Ting
-
-
- Mild environment-friendly oxidative debenzylation of N-benzylanilines using DMSO as an oxidant
-
Oxidative debenzylation of N-benzyl aromatic amines using DMSO as a non-toxic oxidant and catalyzed by TsOH gave Nphenylimines, which were spontaneously hydrolyzed to form anilines and benzaldehydes in good yields. This reaction employs mild, metal-free conditions. The conditions are also suitable for the debenzylation of benzylphenylethers.
- Yoshinaga, Tatsuro,Iwata, Takayuki,Shindo, Mitsuru
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supporting information
p. 191 - 194
(2020/02/25)
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- Photo-Ni-Dual-Catalytic C(sp2)-C(sp3) Cross-Coupling Reactions with Mesoporous Graphitic Carbon Nitride as a Heterogeneous Organic Semiconductor Photocatalyst
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The synergistic combination of a heterogeneous organic semiconductor mesoporous graphitic carbon nitride (mpg-CN) and a homogeneous nickel catalyst with visible-light irradiation at room temperature affords the C(sp2)-C(sp3) cross-co
- Antonietti, Markus,Ghosh, Indrajit,K?nig, Burkhard,Khamrai, Jagadish,Savateev, Aleksandr
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p. 3526 - 3532
(2020/04/09)
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- HETEROCYCLIC COMPOUNDS AS MUTANT IDH INHIBITORS
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The present disclosure relates generally to compounds useful in treatment of conditions associated with mutant isocitrate dehydrogenase (mt-IDH), particularly mutant IDH1 enzymes. Specifically, the present invention discloses compound of formula (IA), which exhibits inhibitory activity against mutant IDH1 enzymes. Method of treating conditions associated with excessive activity of mutant IDH1 enzymes with such compound is disclosed. Uses thereof, pharmaceutical composition, and kits are also disclosed.
- -
-
Paragraph 0532-0533
(2020/07/16)
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- Deoxygenative cross-electrophile coupling of benzyl chloroformates with aryl iodides
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This work describes Ni-catalyzed cross-electrophile coupling of benzyl chloroformate derivatives with aryl iodides that generates a wide range of diaryl methane products. The mild reaction conditions merit the C-O bond radical fragmentation of benzyl chloroformates via halide abstraction or a single electron reduction by a Ni catalyst. This work offers a new substrate type for cross-electrophile couplings.
- Pan, Yingying,Gong, Yuxin,Song, Yanhong,Tong, Weiqi,Gong, Hegui
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supporting information
p. 4230 - 4233
(2019/05/06)
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- Metal-organic layers as multifunctional two-dimensional nanomaterials for enhanced photoredox catalysis
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Metal-organic layers (MOLs) have recently emerged as a novel class of molecular two-dimensional (2D) materials with significant potential for catalytic applications. Herein we report the design of a new multifunctional MOL, Hf12-Ir-Ni, by laterally linking Hf12 secondary building units (SBUs) with photosensitizing Ir(DBB)[dF(CF3)ppy]2+ [DBB-Ir-F, DBB = 4,4′-di(4-benzoato)-2,2′-bipyridine; dF(CF3)ppy = 2-(2,4-difluorophenyl)-5-(trifluoromethyl)pyridine] bridging ligands and vertically terminating the SBUs with catalytic Ni(MBA)Cl2 [MBA = 2-(4′-methyl-[2,2′-bipyridin]-4-yl)acetate] capping agents. Hf12-Ir-Ni was synthesized in a bottom-up approach and characterized by TEM, AFM, PXRD, TGA, NMR, ICP-MS, UV-vis, and luminescence spectroscopy. The proximity between photosensitizing Ir centers and catalytic Ni centers (~0.85 nm) in Hf12-Ir-Ni facilitates single electron transfer, leading to a 15-fold increase in photoredox reactivity. Hf12-Ir-Ni was highly effective in catalytic C-S, C-O, and C-C cross-coupling reactions with broad substrate scopes and turnover numbers of ~4500, ~1900, and ~450, respectively.
- Lan, Guangxu,Quan, Yangjian,Wang, Maolin,Nash, Geoffrey T.,You, Eric,Song, Yang,Veroneau, Samuel S.,Jiang, Xiaomin,Lin, Wenbin
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supporting information
p. 15767 - 15772
(2019/10/11)
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- Structure-Based Optimization of N-Substituted Oseltamivir Derivatives as Potent Anti-Influenza A Virus Agents with Significantly Improved Potency against Oseltamivir-Resistant N1-H274Y Variant
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Due to the emergence of highly pathogenic and oseltamivir-resistant influenza viruses, there is an urgent need to develop new anti-influenza agents. Herein, five subseries of oseltamivir derivatives were designed and synthesized to improve their activity toward drug-resistant viral strains by further exploiting the 150-cavity in the neuraminidases (NAs). The bioassay results showed that compound 21h exhibited antiviral activities similar to or better than those of oseltamivir carboxylate (OSC) against H5N1, H5N2, H5N6, and H5N8. Besides, 21h was 5- to 86-fold more potent than OSC toward N1, N8, and N1-H274Y mutant NAs in the inhibitory assays. Computational studies provided a plausible rationale for the high potency of 21h against group-1 and N1-H274Y NAs. In addition, 21h demonstrated acceptable oral bioavailability, low acute toxicity, potent antiviral activity in vivo, and high metabolic stability. Overall, the above excellent profiles make 21h a promising drug candidate for the treatment of influenza virus infection.
- Zhang, Jian,Murugan, Natarajan Arul,Tian, Ye,Bertagnin, Chiara,Fang, Zengjun,Kang, Dongwei,Kong, Xiujie,Jia, Haiyong,Sun, Zhuosen,Jia, Ruifang,Gao, Ping,Poongavanam, Vasanthanathan,Loregian, Arianna,Xu, Wenfang,Ma, Xiuli,Ding, Xiao,Huang, Bing,Zhan, Peng,Liu, Xinyong
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p. 9976 - 9999
(2018/12/11)
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- Co-immobilization of Laccase and TEMPO in the Compartments of Mesoporous Silica for a Green and One-Pot Cascade Synthesis of Coumarins by Knoevenagel Condensation
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Co-immobilization of bio- and chemocatalysts produces sustainable, recyclable hybrid systems that open new horizons for green cascade approaches in organic synthesis. Here, the co-immobilization of laccase and 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) in mesoporous silica was used for the one-pot aqueous synthesis of 30 coumarin-3-carboxylate derivatives under mild conditions through the condensation of in situ oxidized 2-hydroxybenzyl alcohols and malonate derivatives. A maximum yield was obtained after incubating at pH 6.0 and 45 °C for 24 h. An efficient organic synthesis was catalyzed by the hybrid catalyst in 10 % organic solvent. More than 95 % of the initial activity of the enzyme was preserved after 10 cycles, and no significant catalyst deactivation occurred after 10 runs. This new system efficiently catalyzed the in situ aerobic oxidation of salicyl alcohols, followed by Knoevenagel condensation, which confirmed the possibility of producing efficient hybrid catalysts by co-immobilization of catalytic species in mesoporous materials.
- Mogharabi-Manzari, Mehdi,Amini, Mohsen,Abdollahi, Mohammad,Khoobi, Mehdi,Bagherzadeh, Ghodsieh,Faramarzi, Mohammad Ali
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p. 1542 - 1546
(2018/02/28)
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- Radical-Based C?C Bond-Forming Processes Enabled by the Photoexcitation of 4-Alkyl-1,4-dihydropyridines
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We report herein that 4-alkyl-1,4-dihydropyridines (alkyl-DHPs) can directly reach an electronically excited state upon light absorption and trigger the generation of C(sp3)-centered radicals without the need for an external photocatalyst. Selective excitation with a violet-light-emitting diode turns alkyl-DHPs into strong reducing agents that can activate reagents through single-electron transfer manifolds while undergoing homolytic cleavage to generate radicals. We used this photochemical dual-reactivity profile to trigger radical-based carbon–carbon bond-forming processes, including nickel-catalyzed cross-coupling reactions.
- Buzzetti, Luca,Prieto, Alexis,Roy, Sudipta Raha,Melchiorre, Paolo
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supporting information
p. 15039 - 15043
(2017/11/20)
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- Aerobic Oxidation of 4-Alkyl-N,N-dimethylbenzylamines Catalyzed by N-Hydroxyphthalimide: Protonation-Driven Control over Regioselectivity
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A change in regioselectivity has been observed in the hydrogen atom transfer (HAT) reactions from 4-alkyl-N,N-dimethylbenzylamines (alkyl = ethyl, isopropyl, and benzyl) to the phthalimide N-oxyl radical (PINO) by effect of protonation. This result can be rationalized on the basis of an acid-induced deactivation of the C-H bonds α to nitrogen toward HAT to PINO as evidenced by the 104-107-fold decrease in the HAT rate constants in acetonitrile following addition of 0.1 M HClO4. This acid-induced change in regioselectivity has been successfully applied for selective functionalization of the less activated benzylic C-H bonds para to the CH2N(CH3)2 group in the aerobic oxidation of 4-alkyl-N,N-dimethylbenzylamines catalyzed by N-hydroxyphthalimide in acetic acid.
- Bietti, Massimo,Lanzalunga, Osvaldo,Lapi, Andrea,Martin, Teo,Mazzonna, Marco,Polin, Mariangela,Salamone, Michela
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p. 5761 - 5768
(2017/06/07)
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- Probing the Azaaurone Scaffold against the Hepatic and Erythrocytic Stages of Malaria Parasites
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The potential of azaaurones as dual-stage antimalarial agents was investigated by assessing the effect of a small library of azaaurones on the inhibition of liver and intraerythrocytic lifecycle stages of the malaria parasite. The whole series was screened against the blood stage of a chloroquine-resistant Plasmodium falciparum strain and the liver stage of P. berghei, yielding compounds with dual-stage activity and sub-micromolar potency against erythrocytic parasites. Studies with genetically modified parasites, using a phenotypic assay based on the P. falciparum Dd2-ScDHODH line, which expresses yeast dihydroorotate dehydrogenase (DHODH), showed that one of the azaaurone derivatives has the potential to inhibit the parasite mitochondrial electron-transport chain. The global urgency in finding new therapies for malaria, especially against the underexplored liver stage, associated with chemical tractability of azaaurones, warrants further development of this chemotype. Overall, these results emphasize the azaaurone chemotype as a promising scaffold for dual-stage antimalarials.
- Carrasco, Marta P.,Machado, Marta,Gon?alves, Lídia,Sharma, Moni,Gut, Jiri,Lukens, Amanda K.,Wirth, Dyann F.,André, Vania,Duarte, Maria Teresa,Guedes, Rita C.,dos Santos, Daniel J. V. A.,Rosenthal, Philip J.,Mazitschek, Ralph,Prudêncio, Miguel,Moreira, Rui
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supporting information
p. 2194 - 2204
(2016/10/19)
-
- Controlled Reduction of Tertiary Amides to the Corresponding Alcohols, Aldehydes, or Amines Using Dialkylboranes and Aminoborohydride Reagents
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Dialkylboranes and aminoborohydrides are mild, selective reducing agents complementary to the commonly utilized amide reducing agents, such as lithium aluminum hydride (LiAlH4) and diisobutylaluminum hydride (DIBAL) reagents. Tertiary amides were reduced using 1 or 2 equiv of various dialkylboranes. The reduction of tertiary amides required 2 equiv of 9-borabicyclo[3.3.1]nonane (9-BBN) for complete reduction to give the corresponding tertiary amines. One equivalent of sterically hindered disiamylborane reacts with tertiary amides to afford the corresponding aldehydes. Aminoborohydrides are powerful and selective reducing agents for the reduction of tertiary amides. Lithium dimethylaminoborohydride and lithium diisopropylaminoborohydride are prepared from n-butyllithium and the corresponding amine-borane. Chloromagnesium dimethylaminoborohydride (ClMg+[H3B-NMe2]-, MgAB) is prepared by the reaction of dimethylamine-borane with methylmagnesium chloride. Solutions of aminoborohydride reduce aliphatic, aromatic, and heteroaromatic tertiary amides to give the corresponding alcohol, amine, or aldehyde depending on the steric requirement of the tertiary amide and the aminoborohydride used.
- Bailey, Christopher L.,Joh, Alexander Y.,Hurley, Zefan Q.,Anderson, Christopher L.,Singaram, Bakthan
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p. 3619 - 3628
(2016/05/24)
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- Donor-Acceptor Fluorophores for Visible-Light-Promoted Organic Synthesis: Photoredox/Ni Dual Catalytic C(sp3)-C(sp2) Cross-Coupling
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We describe carbazolyl dicyanobenzene (CDCB)-based donor-acceptor (D-A) fluorophores as a class of cheap, easily accessible, and efficient metal-free photoredox catalysts for organic synthesis. By changing the number and position of carbazolyl and cyano groups on the center benzene ring, CDCBs with a wide range of photoredox potentials are obtained to effectively drive the energetically demanding C(sp3)-C(sp2) cross-coupling of carboxylic acids and alkyltrifluoroborates with aryl halides via a photoredox/Ni dual catalysis mechanism. This work validates the utility of D-A fluorophores in guiding the rational design of metal-free photoredox catalysts for visible-light-promoted organic synthesis.
- Luo, Jian,Zhang, Jian
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p. 873 - 877
(2016/02/18)
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- Cobalt co-catalysis for cross-electrophile coupling: Diarylmethanes from benzyl mesylates and aryl halides
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The nickel-catalyzed cross-coupling of aryl halides with alkyl radicals derived from alkyl halides has recently been extended to couplings with carbon radicals generated by a co-catalyst. In this study, a new co-catalyst, cobalt phthalocyanine (Co(Pc)), is introduced and demonstrated to be effective for coupling substrates not prone to homolysis. This is because Co(Pc) reacts with electrophiles by an SN2 mechanism instead of by the electron-transfer or halogen abstraction mechanisms previously explored. Studies demonstrating the orthogonal reactivity of (bpy)Ni and Co(Pc), applying this selectivity to the coupling of benzyl mesylates with aryl halides, and the adaptation of these conditions to the less reactive benzyl phosphate ester and an enantioconvergent reaction are presented.
- Ackerman, Laura K. G.,Anka-Lufford, Lukiana L.,Naodovic, Marina,Weix, Daniel J.
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p. 1115 - 1119
(2015/02/05)
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- Single-electron transmetalation in organoboron cross-coupling by photoredox/nickel dual catalysis
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The routine application of Csp3-hybridized nucleophiles in cross-coupling reactions remains an unsolved challenge in organic chemistry. The sluggish transmetalation rates observed for the preferred organoboron reagents in such transformations are a consequence of the two-electron mechanism underlying the standard catalytic approach. We describe a mechanistically distinct single-electron transfer-based strategy for the activation of organoboron reagents toward transmetalation that exhibits complementary reactivity patterns. Application of an iridium photoredox catalyst in tandem with a nickel catalyst effects the cross-coupling of potassium alkoxyalkyl- and benzyltrifluoroborates with an array of aryl bromides under exceptionally mild conditions (visible light, ambient temperature, no strong base). The transformation has been extended to the asymmetric and stereoconvergent cross-coupling of a secondary benzyltrifluoroborate.
- Tellis, John C.,Primer, David N.,Molander, Gary A.
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p. 433 - 436
(2014/08/05)
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- Palladium-catalyzed benzylation of arylboronic acids with N,N-ditosylbenzylamines
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The palladium-catalyzed coupling of N,N-ditosylbenzylamines with arylboronic acids has been investigated, and the resulting diarylmethanes were obtained in high yields. Conversion of the amine to a N,N-ditosylimide group provided an efficient leaving group for the Pd-catalyzed benzylation of arylboronic acids.
- Yoon, Sangeun,Hong, Myeng Chan,Rhee, Hakjune
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p. 4206 - 4211
(2014/05/20)
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- Identification, design and biological evaluation of bisaryl quinolones targeting Plasmodium falciparum type II NADH:Quinone oxidoreductase (PfNDH2)
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A program was undertaken to identify hit compounds against NADH:ubiquinone oxidoreductase (PfNDH2), a dehydrogenase of the mitochondrial electron transport chain of the malaria parasite Plasmodium falciparum. PfNDH2 has only one known inhibitor, hydroxy-2-dodecyl-4-(1H)-quinolone (HDQ), and this was used along with a range of chemoinformatics methods in the rational selection of 17 000 compounds for high-throughput screening. Twelve distinct chemotypes were identified and briefly examined leading to the selection of the quinolone core as the key target for structure-activity relationship (SAR) development. Extensive structural exploration led to the selection of 2-bisaryl 3-methyl quinolones as a series for further biological evaluation. The lead compound within this series 7-chloro-3-methyl-2-(4-(4-(trifluoromethoxy)benzyl)phenyl) quinolin-4(1H)-one (CK-2-68) has antimalarial activity against the 3D7 strain of P. falciparum of 36 nM, is selective for PfNDH2 over other respiratory enzymes (inhibitory IC50 against PfNDH2 of 16 nM), and demonstrates low cytotoxicity and high metabolic stability in the presence of human liver microsomes. This lead compound and its phosphate pro-drug have potent in vivo antimalarial activity after oral administration, consistent with the target product profile of a drug for the treatment of uncomplicated malaria. Other quinolones presented (e.g., 6d, 6f, 14e) have the capacity to inhibit both PfNDH2 and P. falciparum cytochrome bc1, and studies to determine the potential advantage of this dual-targeting effect are in progress.
- Pidathala, Chandrakala,Amewu, Richard,Pacorel, Bénédicte,Nixon, Gemma L.,Gibbons, Peter,Hong, W. David,Leung, Suet C.,Berry, Neil G.,Sharma, Raman,Stocks, Paul A.,Srivastava, Abhishek,Shone, Alison E.,Charoensutthivarakul, Sitthivut,Taylor, Lee,Berger, Olivier,Mbekeani, Alison,Hill, Alasdair,Fisher, Nicholas E.,Warman, Ashley J.,Biagini, Giancarlo A.,Ward, Stephen A.,O'Neill, Paul M.
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supporting information; experimental part
p. 1831 - 1843
(2012/05/04)
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- ANTIMALARIAL COMPOUNDS
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The present invention relates to antimalarial compounds. More specifically, the present invention relates to novel substituted quinolone derivatives of formula (I) and related quinoline derivatives of formula (II) as defined herein that possess potent ant
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Page/Page column 51; 53
(2012/06/15)
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- Palladium nanoparticle catalyzed hiyama coupling reaction of benzyl halides
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An efficient Hiyama coupling reaction between benzylic halide and aryltrialkoxysilane using Pd nanoparticles has been developed. This procedure accommodates various functional groups to yield a diverse range of diarylmethanes which are ubiquitous units of natural products and pharmaceuticals.
- Srimani, Dipankar,Bej, Ansuman,Sarkar, Amitabha
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supporting information; experimental part
p. 4296 - 4299
(2010/09/04)
-
- NOVEL GLUCOCORTICOID RECEPTOR AGONISTS
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This invention relates to novel glucocorticoid receptor agonists of formula (I) and to processes and intermediates for their preparation. The present invention also relates to pharmaceutical compositions containing these compounds, to their combination with one or more other therapeutic agents, as well as to their use for the treatment of a number of inflammatory and allergic diseases, disorders and conditions.
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Page/Page column 33
(2009/07/03)
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- Suzuki-miyaura cross-coupling reactions of benzyl halides with potassium aryltrifluoroborates
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(Chemical Equation Presented) The palladium-catalyzed cross-coupling of potassium aryltrifluoroborates with benzylic halides occurs in good yield with high functional group tolerance. The increased stability of potassium aryltrifluoroborates compared to other boron coupling partners makes this an effective route to functionalized methylene-linked biaryl systems.
- Molander, Gary A.,Elia, Maxwell D.
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p. 9198 - 9202
(2007/10/03)
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- Organic compounds
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Novel compounds that inhibit the binding of the Smac protein to Inhibitor of Apoptosis Proteins (IAPs) of the formula I
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Page/Page column 12; 24
(2008/06/13)
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- Palladium-catalyzed cross-coupling of B-Benzyl-9-borabicyclo[3.3.1]nonane to furnish methylene-linked biaryls
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(Chemical Equation Presented) Benzylboranes are noticeably uncommon partners within Suzuki-Miyaura coupling reactions. B-Benzyl-9-BBN was successfully coupled to a range of aryl/heteroaryl bromides, chlorides, and triflates to give pharmacologically important methylene-linked biaryl structures. Activated, deactivated, and sterically hindered substrates were successfully coupled in high yield using Pd(PPh3)4 or Pd(OAc)2 with SPhos as the catalyst system.
- Flaherty, Alice,Trunkfield, Amy,Barton, William
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p. 4975 - 4978
(2007/10/03)
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- Carbocyclic and heterocyclic substituted semicarbazones and thiosemicarbazones and the use thereof
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This invention is related to carbocyclic and heterocyclic substituted semicarbazones and thiosemicarbazones represented by Formula I: or a pharmaceutically acceptable salt or prodrug thereof, wherein: Y is oxygen or sulfur; R1, R21, R22 and R23 are independently hydrogen, alkyl, cycloalkyl, alkenyl, alkynyl, haloalkyl, aryl, aminoalkyl, hydroxyalkyl, alkoxyalkyl or carboxyalkyl; or R22 and R23, together with the N, form a heterocycle; A1 and A2 are independently aryl, heteroaryl, saturated or partially unsaturated carbocycle or saturated or partially unsaturated heterocycle, any of which is optionally substituted; X is one or O, S, NR24, CR25R26, C(O), NR24C(O), C(O)NR24, SO, SO2 or a covalent bond; where R24, R25 and R26 are independently hydrogen, alkyl, cycloalkyl, alkenyl, alkynyl, haloalkyl, aryl, aminoalkyl, hydroxyalkyl, alkoxyalkyl or carboxyalkyl. The invention also is directed to the use of carbocycle and heterocycle substituted semicarbazones and thiosemicarbazones for the treatment of neuronal damage following global and focal ischemia, for the treatment or prevention of neurodegenerative conditions such as amyotrophic lateral sclerosis (ALS), for the treatment and prevention of otoneurotoxicity and eye diseases involving glutamate toxicity and for the treatment, prevention or amelioration of pain, as anticonvulsants, and as antimanic depressants, as local anesthetics, as antiarrhythmics and for the treatment or prevention of diabetic neuropathy and urinary incontinence.
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- Structure-activity relationship studies on 1-[2-(4- phenylphenoxy)ethyl]pyrrolidine (SC-22716), a potent inhibitor of leukotriene A4 (LTA4) hydrolase
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Leukotriene B4 (LTB4) is a pro-inflammatory mediator that has been implicated in the pathogenesis of a number of diseases including inflammatory bowel disease (IBD) and psoriasis. Since the action of LTA4 hydrolase is the rate-limiting step for LTB4 production, this enzyme represents an attractive pharmacological target for the suppression of LTB4 production. From an in- house screening program, SC-22716 (1, 1-[2-(4- phenylphenoxy)ethyl]pyrrolidine) was identified as a potent inhibitor of LTA4 hydrolase. Structure-activity relationship (SAR) studies around this structural class resulted in the identification of a number of novel, potent inhibitors of LTA4 hydrolase, several of which demonstrated good oral activity in a mouse ex vivo whole blood assay.
- Penning, Thomas D.,Chandrakumar, Nizal S.,Chen, Barbara B.,Chen, Helen Y.,Desai, Bipin N.,Djuric, Stevan W.,Docter, Stephen H.,Gasiecki, Alan F.,Haack, Richard A.,Miyashiro, Julie M.,Russell, Mark A.,Yu, Stella S.,Corley, David G.,Durley, Richard C.,Kilpatrick, Brian F.,Parnas, Barry L.,Askonas, Leslie J.,Gierse, James K.,Harding, Elizabeth I.,Highkin, Maureen K.,Kachur, James F.,Kim, Suzanne H.,Krivi, Gwen G.,Villani-Price, Doreen,Pyla, E. Yvonne,Smith, Walter G.,Ghoreishi-Haack, Nayereh S.
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p. 721 - 735
(2007/10/03)
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- Influence of Conformation and Proton-Transfer Dynamics in the Dibenzyl σ-Complex on Regioselectivity in Gattermann-Koch Formylation via Intracomplex Reaction
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The Gattermann-Koch formylations of diphenyl, diphenylmethane, dibenzyl, and 1,3-diphenyl- propane were studied in HF-SbF5, -TaF5, -BF3, -NbF5, and CF3SO3H-SbF5. While usual high para regioselectivity was obtained for diphenyl, diphenylmethane, and 1,3-diphenylpropane, unprecedented ortho regioselectivity was observed for dibenzyl which increased with decreasing the SbF5/dibenzyl molar ratio and with strength of Lewis acids used in HF. A sandwich-like complex for monoprotonated dibenzyl resulting in ortho regioselectivity via the intracomplex reaction was suggested; therefore, the conformations of protonated diphenylmethane, dibenzyl, and 1,3- diphenylpropane and their proton-transfer dynamics were probed by semiempirical calculation (PM3). The calculation predicted that ortho monoprotonation was slightly preferable for dibenzyl, and remarkable preference of dibenzyl over other aromatic compounds was observed in ortho- ortho intramolecular inter-ring proton transfer via a fan-shaped complex rather than a sandwich- like complex. The experimental and theoretical data for dibenzyl are compatible with the intracomplex reaction, whereby CO is protonated by the ortho σ-complex undergoing rapid inter- ring proton transfer to generate formyl cation in the vicinity of the ortho position leading to ortho regioselectivity.
- Tanaka, Mutsuo,Fujiwara, Masahiro,Xu, Qiang,Ando, Hisanori,Raeker, Todd J.
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p. 4408 - 4412
(2007/10/03)
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- Pesticidal cyclopropyl-2,4-dieneamides
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The present Application discloses pesticidally active compounds of the formula (I): or a salt thereof, wherein Q is an monocyclic aromatic ring. or fused bicyclic ring system of which at least one ring is aromatic containing 9 or 10 atoms of which one may be nitrogen and the rest carbon each optionally substituted, or Q is a dihalovinyl group or a group R6 --C C-- where R6 is C1-4 alkyl, tri C1-4 alkylsilyl, halogen or hydrogen; Q1 is a 1,2-cyclopropyl ring optionally substituted by one or more groups selected from C1-3 alkyl. halo, C1-3 haloalkyl, alkynyl, or cyano; R2,R3, R4 and R5 are the same or different with at least one being hydrogen and the others being independently selected from hydrogen, halo. C1-4 alkyl or C1-4 haloalkyl; X is oxygen or sulphur; and R1 is selected from hydrogen and C1-8 hydrocarbyl optionally substituted by dioxalanyl, halo, cyano, trifluoromethyl, trifluoromethylthio or C1-6 alkoxy. their preparation, pesticidal compositions containing them and their use against pests.
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- (1.1.1.1.1)PARACYCLOPHANE AND (1.1.1.1.1.1)PARACYCLOPHANE
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The first syntheses of (1.1.1.1.1)paracyclophane (1) and (1.1.1.1.1.1)paracyclophane (2) are described, featuring a trifluoroacetic acid promoted Friedel-Crafts cycloalkylation as the final step.
- Gribble, Gordon W.,Nutaitis, Charles F.
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p. 6023 - 6026
(2007/10/02)
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