- New Bidentate N-Sulfonyl-Substituted Aromatic Amines as Chelate Ligand Backbones: Pd Catalyst Generation in C-C Coupling via in Situ and Precatalyst Modes
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A series of six new, bidentate ligands based on N-(2-(R-sulfonamido)benzyl)R-sulfonamide have been isolated as dianionic or monoanionic chelators via condensation of 2-(aminomethyl)aniline with sulfonyl chloride reagents; R = methyl (1 and 1′), tolyl (2 and 2′), 2,4,6-Trimethylphenyl (3), or 2,4,6-Triisopropylphenyl (4). Complexes of ligands 2-4 reacted at room temperature with palladium(ii) acetate in the presence of various monodentate N-donor co-ligands to form complexes Pd2(2dmap), Pd2′(OAc.py), Pd3(2acn), Pd3(2py), Pd4(2acn), and Pd4(2py), which were structurally confirmed by three X-ray crystal analyses. Results of catalysis studies in water showed high turnover frequencies and yields of up to 98 % within 10 min and at 0.2 mol-% palladium catalyst loading. Relative to ligand-free catalysis in the presence of only Pd(OAc)2, the ligand-supported palladium species clearly possess positive catalytic advantage. Furthermore, Suzuki coupling efficiencies by 1: 1 'Pd(OAc)2 + ligand' yielded notably better outcomes than for the 1: 2 'Pd(OAc)2 + ligand' in situ catalyst generation, which reveals that coordinative saturation is undesirable. The size of the complementing monodentate co-ligand was observed to influence the catalytic efficiency such that bulkier co-ligands consistently yielded improved turnover frequency values, which leads to the conclusion that steric repulsion between the synthesised ligands and the bulkier co-ligands aided the generation of vacant coordination sites for the more active complexes. Moderate Heck coupling activity was recorded for the complexes and better activities appear to correlate with moderate bulkiness of ligand 3.
- Oloyede, Hammed Olawale,Akong Akong, Raymond,Woods, Joseph Anthony Orighomisan,G?rls, Helmar,Plass, Winfried,Eseola, Abiodun Omokehinde
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p. 101 - 110
(2020/07/28)
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- N-donor-stabilized Pd(II) species supported by sulphonamide-azo ligands: Ligand architecture, solvent co-ligands, C–C coupling
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In this report, a series of synthetically affordable phosphine-free ligands (L1 – L4) of the form RSO2–NH–Ph–N[dbnd]N–Ph–NH–SO2R were prepared and examined as organic ligands for stabilizing palladium active centers; R = methyl, tolyl or triiso-propylphenyl. Palladium complexes, which were obtained in varying coordination environments as well as with varying complementary co-ligands (water, acetonitrile or pyridine), have been subjected to Suzuki and Heck coupling experiments in order to study molecular level ligand effects on preferred catalyst settings. The appreciable coupling activities for Suzuki and Heck coupling with functional group tolerance were recorded for palladium species generated from the chelate ligands. Results show that, despite the tridentate chelation characteristics of these azo-benzene ligands, the introduction of bulky units at the sulfonyl groups enabled generation of active palladium species with high turnover frequencies; e.g. 5040 h?1 (84% yield) within 5 min at 0.2 mol % loading of Pd.L2.py in only water as solvent. A correlation between catalytic efficiencies and the bulkiness of the coordinated co-ligand was obtained. However, while Suzuki coupling activity increased with increase in co-ligand sizes of the preformed complexes (i.e. water acetonitrile pyridine), the pyridyl co-ligand turned out to be very unfavourable for Heck coupling where the acetonitrile-complemented complexes possessed the higher activities. Therefore, it could be concluded that the best catalyst setting for Suzuki coupling may not be the best for Heck reaction.
- Oloyede, Hammed Olawale,Orighomisan Woods, Joseph Anthony,G?rls, Helmar,Plass, Winfried,Eseola, Abiodun Omokehinde
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- THERAPEUTIC COMPOUNDS AND METHODS TO TREAT INFECTION
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Disclosed herein are compounds of formula I: or a salt thereof and compositions comprising a compound of formula I or a pharmaceutically acceptable salt thereof. Also disclosed herein are methods for treating or preventing a bacterial infection in an animal comprising administering to the animal a compound of formula I or a pharmaceutically acceptable salt thereof, alone or in combination with a bacterial efflux pump inhibitor.
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Paragraph 0426-0427
(2019/02/13)
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- Importance of monodentate mono-ligand designs in developing N-stabilized Pd catalysts for efficient ambient temperature C[sbnd]C coupling: Donor strengths and steric features
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Unfriendly temperature profiles and costs of carbon coupling catalysis, which pose challenge to both synthetic organic chemists as well as industrial applicability, motivated our design of new monodentate N-donors as support ligands for the purpose of constructing ambient temperature precatalysts that are molecularly close to the hypothetical active forms. Therefore, a series of sterically varied monodentate N-donor imidazoles (1–7) and oxazoles (8–9) have been synthesized and their N-donor strengths, which were estimated as pKas, are systematically varied from 0.9 to 8.5 by substituent variations. Eleven target mono-ligand complexes (1-PdCl2MeCN – 9-PdCl2MeCN, 6-PdCl2PhCN and 7-PdCl2PhCN) and six trans-bis-ligand complexes (12-PdCl2, 22-PdCl2, 32-PdCl2, 62-PdCl2, 12-Pd(OAc)2 and 22-Pd(OAc)2) were isolated and catalytically studied along with PdI2(PPh3)2. Results of coupling reactions, which were conducted both via in situ ‘Pd(II) salt + ligand’ approach and by use of the precatalysts, show that the mono-ligand precatalyst designs (1-PdCl2MeCN – 9-PdCl2MeCN, 6-PdCl2PhCN and 7-PdCl2PhCN) represent a true catalyst improvement initiative among the phosphine-free catalyst community; i.e. yields approaching 100% (TOF ≈ 2000) at 0.2 mol % catalyst loading, 45 °C and within 15 min. On the other hand, the complexes with trans-bis-ligand coordination were inactive at ambient temperatures. Therefore, it was concluded that coordinative saturation, which results from implementing two or more ligand equivalents or use of polydentate ligands on palladium, should be strongly discouraged. Such saturation necessitates the undesirable and avoidable high temperature necessities, long reflux durations and needlessly high catalyst loadings. Correlation between catalyst activity and donor strengths or steric properties were analysed leading to important conclusions. The catalyst design also supported coupling of activated aryl chlorides from 60 °C while Heck coupling activities were observed only at the early minutes of reactions.
- Eseola, Abiodun Omokehinde,G?rls, Helmar,Plass, Winfried
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- N-donor 2-(Sulfonamido)benzamide ligands, their palladium(II) coordination species and C–C coupling catalysis efficiencies
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A series of synthetically accessible ligands based on new 2-(R-sulfonamido)benzamide have been prepared (R = methyl for H3M; R = 4-toly for H3T and T2CN; R = 2,4,6-triisopropylphenyl for H3iP and HiPCN). The R-substituents were selected to vary in sizes. Allowing ligand H3iP and palladium acetate to stand in solvent leads to self-assembly of the well-defined solvent- and stoichiometry-controlled tetranuclear or hexanuclear coordination macromolecules Pd4(iP)2 and (PdHiP)6, which were analysed by X-ray crystallography. It was observed that palladium active species for Suzuki coupling catalysis could be stabilized by these simple and synthetically assessable N-donor ligands as revealed by turnover frequencies reaching 5500 h?1. Electronic features of these N-donors appear to be more important than the steric properties.
- Oloyede, Hammed Olawale,G?rls, Helmar,Orighomisan Woods, Joseph Anthony,Plass, Winfried,Eseola, Abiodun Omokehinde
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p. 336 - 344
(2019/07/31)
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- CERAMIDE GALACTOSYLTRANSFERASE INHIBITORS FOR THE TREATMENT OF DISEASE
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Described herein are compounds, methods of making such compounds, pharmaceutical compositions and medicaments containing such compounds, and methods of using such compounds to treat or prevent diseases or disorders associated with the enzyme ceramide galactosyltransferase (CGT), such as, for example, lysosomal storage diseases. Examples of lysosomal storage diseases include, for example, Krabbe disease and Metachromatic Leukodystrophy.
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Paragraph 00498-00500
(2019/06/11)
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- COMPOSITIONS, METHODS, AND SYSTEMS FOR THE SYNTHESIS AND USE OF IMAGING AGENTS
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The present invention provides compounds with imaging moieties for imaging a subject. The present invention also relates to systems, compositions, and methods for the synthesis and use of imaging agents, or precursors thereof. An imaging agent precursor may be converted to an imaging agent using the methods described herein. In some cases, a composition or plurality of imaging agents is enriched in 18 F. In some cases, an imaging agent may be used to image an area of interest in a subject, including, but not limited to, the heart, cardiovascular system, cardiac vessels, brain, and other organs.
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Paragraph 1551
(2015/07/22)
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- Contrast agent and for the use of a synthetic composition, method and system (by machine translation)
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The present invention provides compounds with imaging moieties for imaging a subject. The present invention also relates to systems, compositions, and methods for the synthesis and use of imaging agents, or precursors thereof. An imaging agent precursor may be converted to an imaging agent using the methods described herein. In some cases, a composition or plurality of imaging agents is enriched in 18 F. In some cases, an imaging agent may be used to image an area of interest in a subject, including, but not limited to, the heart, cardiovascular system, cardiac vessels, brain, and other organs.
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Paragraph 0597
(2016/10/07)
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- Synthesis, biological evaluation, and 3D QSAR study of 2-methyl-4-oxo-3-oxetanylcarbamic acid esters as N -acylethanolamine acid amidase (NAAA) inhibitors
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N-(2-Oxo-3-oxetanyl)carbamic acid esters have recently been reported to be noncompetitive inhibitors of the N-acylethanolamine acid amidase (NAAA) potentially useful for the treatment of pain and inflammation. In the present study, we further explored the
- Ponzano, Stefano,Berteotti, Anna,Petracca, Rita,Vitale, Romina,Mengatto, Luisa,Bandiera, Tiziano,Cavalli, Andrea,Piomelli, Daniele,Bertozzi, Fabio,Bottegoni, Giovanni
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supporting information
p. 10101 - 10111
(2015/02/02)
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- Pyrimidinone compounds
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Pyrimidinone compounds of formula (I) are inhibitors of the enzyme Lp-PLA2 and of use in therapy, in particular for treating atherosclerosis.
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Page/Page column 19
(2008/06/13)
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- Compounds that modulate PPAR activity and methods for their preparation
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This invention discloses compounds that alter PPAR activity. The invention also discloses pharmaceutically acceptable salts of the compounds, pharmaceutically acceptable compositions comprising the compounds or their salts, and methods of using them as therapeutic agents for treating or preventing disipidemia, hypercholesteremia, obesity, eating disorders, hyperglycemia, atherosclerosis, hypertriglyceridemia, hyperinsulinemia and diabetes in a mammal as well as methods of supressing appetite and modulating leptin levels in a mammal. The present invention also discloses methods for making the disclosed compounds.
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- Isoquinolyl substituted hydroxylamine derivatives
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The compounds of the formula STR1 wherein R represents hydrogen, lower alkyl, aryl, biaryl, C3 -C7 -cycloalkyl, aryl-lower alkyl, aryl-lower alkenyl, aryl-lower alkynyl, aryloxy-lower alkyl, arylthio-lower alkyl, C3 -Csub
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- ISOQUINOLYL SUBSTITUTED HYDROXYLAMINE DERIVATIVES
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The compounds of the formula wherein R represents hydrogen, lower alkyl, aryl, biaryl, C3-C7-cycloalkyl, aryl-lower alkyl, aryl-lower alkenyl, aryl-lower alkynyl, aryloxy-lower alkyl, arylthio-lower alkyl; C3-C7-cycloalkyl-lower alkyl, biaryl-lower alkyl,
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