- A three step continuous flow synthesis of the biaryl unit of the HIV protease inhibitor Atazanavir
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The development of multistep continuous flow reactions for the synthesis of important intermediates for the pharmaceutical industry is still a significant challenge. In the present contribution the biaryl-hydrazine unit of Atazanavir, an important HIV protease inhibitor, was prepared in a three-step continuous flow sequence in 74% overall yield. The synthesis involved Pd-catalyzed Suzuki-Miyaura cross-coupling, followed by hydrazone formation and a subsequent hydrogenation step, and additionally incorporates a liquid-liquid extraction step.
- Dalla-Vechia, Luciana,Reichart, Benedikt,Glasnov, Toma,Miranda, Leandro S. M.,Kappe, C. Oliver,De Souza, Rodrigo O. M. A.
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- A scalable synthesis of biaryl unit of the HIV protease inhibitor atazanavir
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Atazanavir is one of the most prescribed HIV-1 protease inhibitors approved by the FDA. It was the first protease inhibitor approved for once-a-day dosing to treat AIDS due to good oral bioa-vailability and favorable pharmacokinetic profile. This research aims to develop a new synthetic cost effective process for biaryl-hydrazine unit {tert-butyl 2-[4-(2-pyridinyl)benzyl]hydrazinecarboxylate} of atazanavir on a large scale. The synthesis involved palladium catalyzed Suzuki-Miyaura coupling of 2-chloropyridine and (4-cyanophenyl)boronic acid followed by DIBAL-H reduction of cyano group to aldehyde which is then treated with tert-butyl carbazate to furnish hydrazone subsequently in situ reduction with NaBH4. A large scale synthesis of biaryl-hydrazine unit of atazanavir was accomplished in three steps with 71% overall yield. We have developed a short and efficient synthesis of atazanavir key intermediate biaryl-hydrazine unit. The process does not require the usage of Grignard reagent, expensive catalyst, protection/deprotection of aldehyde moiety and catalytic hydrogenation.
- Katari, Naresh K.,Prasad, Malavattu G.,Reddy, Pedavenkatagari N.,Vijayalakshmi, Chapala
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- Synthesis of phosphoramidates: A facile approach based on the C-N bond formation via Ir-catalyzed direct C-H amidation
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A new synthetic route to phosphoramidates by intermolecular C-H amidation is presented. Substrates with assorted directing groups were activated by an iridium-based catalyst system and reacted with a number of phosphoryl azides, executing efficient phosphoramidate synthesis via C-N bond formations. (Chemical Equation Presented).
- Kim, Hyunwoo,Park, Juhyeon,Kim, Jeung Gon,Chang, Sukbok
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- A simple synthetic entryway into palladium cross-coupling catalysis
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The simple synthesis of a family of palladates containing an imidazolium counterion is presented. These "ate" complexes can be easily converted into well-defined palladium-N-heterocyclic carbene (NHC) complexes. The synthetic protocols leading to the "ate
- Zinser, Caroline M.,Nahra, Fady,Brill, Marcel,Meadows, Rebecca E.,Cordes, David B.,Slawin, Alexandra M. Z.,Nolan, Steven P.,Cazin, Catherine S. J.
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- Calix[6]arene derivatives selectively functionalized at alternate sites on the smaller rim with 2-phenylpyridine and 2-fluorenylpyridine substituents to provide deep cavities
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The synthesis is described of calix[6]arene derivatives 4, 9, and 14 functionalized at alternate sites on the smaller rim with 4′-(pyrid- 2″-yl)phenylmethoxy, (6′-phenylpyrid-3′-ylmethoxy), and {6′-[2-(9,9-di-n-hexylfluorenyl)]pyrid-3′-ylmethoxy} substitu
- Zeng, Xianshun,Batsanov, Andrei S.,Bryce, Martin R.
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- UV Light Generation and Challenging Photoreactions Enabled by Upconversion in Water
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Sensitized triplet-triplet annihilation (sTTA) is the most promising mechanism for pooling the energy of two visible photons, but its applications in solution were so far limited to organic solvents, with a current maximum of the excited-singlet state energy of 3.6 eV. By combining tailor-made iridium complexes with naphthalenes, we demonstrate blue-light driven upconversion in water with unprecedented singlet-state energies approaching 4 eV. The annihilators have outstanding excited-state reactivities enabling challenging photoreductions driven by sTTA. Specifically, we found that an aryl-bromide bond activation can be achieved with blue photons, and we obtained full conversion for the very energy-demanding decomposition of a persistent ammonium compound as typical water pollutant, not only with a cw laser but also with an LED light source. These results provide the first proof-of-concept for the usage of low-power light sources for challenging reactions employing blue-to-UV upconversion in water and pave the way for the further development of sustainable light-harvesting applications.
- Pfund, Bj?rn,Steffen, Debora M.,Schreier, Mirjam R.,Bertrams, Maria-Sophie,Ye, Chen,B?rjesson, Karl,Wenger, Oliver S.,Kerzig, Christoph
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- Salicylaldehyde-based anion sensors featuring turn-on fluorescence, colorimetry, and the anti-counterfeiting application
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Two simple salicylaldehyde-based sensors BDQ and BQ were developed, which had been applied in anion sensing and anti-counterfeiting. Their chemical structures were determined by the 1H, 13C NMR and mass spectra. In the anion sensing
- Chen, Qiaobin,Li, Chencheng,Wu, Jianglan,Zhao, Jiang
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- Synthesis, thermal and optical properties of a novel bis(2-(4-dicyanovinylphenyl)pyridinato-N,C2)iridium(acetylacetonate)
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Bis(2-(4-formylphenyl)pyridinato-N,C2)iridium(acetylacetonate) (5) was subjected to a Knoevenagel reaction with malononitrile in dichloromethane in the presence of catalytic amount of pyrrolidine. This gave successfully a novel bis(2-(4-dicyanovinylphenyl
- Altin?l?ek, Nuray,Tavasli, Mustafa,Aydemir, Murat,Abay, Bahattin,Monkman, Andrew P.
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- Synthesis of new bioorganometallic Ir- and Rh-complexes having β-lactam containing ligands
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The synthesis (and full spectroscopic and crystallographic characterization) of new classes of bioorganometallic Ir- and Rh-complexes having β-lactam containing ligands has been achieved in three steps starting from simple precursors. The procedure for preparing these bioorganometallic compounds uses β-lactams having a phenylpyridyl moiety attached to the C4, N1 or C4 and N1 positions simultaneously, and a directed C-H metal-insertion, in the presence of (MCp*Cl2)2 (M = Ir, Rh). Enantiomerically pure 2-azetidinones can be transformed into diastereomeric (at the metal) mixtures of enantiopure metalla-2-azetidinones. Bimetallic 2-azetidinones are also accessible by this approach. The insertion of electron-poor alkynes into the M-C bond of the bioorganometallic complex occurs regioselectively and in excellent yields. Overall, the sequence imine-β-lactam-metalla-β-lactam is a versatile and efficient full methodology to prepare and functionalize unprecedented, novel Ir- and Rh-complexes having β-lactam containing ligands.
- Muntaner, Jaime G.,Casarrubios, Luis,Sierra, Miguel A.
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- Insights into the Catalytic Activity of [Pd(NHC)(cin)Cl] (NHC=IPr, IPrCl, IPrBr) Complexes in the Suzuki–Miyaura Reaction
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The influence of C4,5-halogenation on palladium N-heterocyclic carbene complexes and their activity in the Suzuki–Miyaura reaction were investigated. Two [Pd(NHC)(cin)Cl] complexes bearing IPrCl and IPrBr ligands (IPr=1,3-bis(2,6-diisopropyl-phenyl)imidazol-2-ylidene; cin=cinnamyl) were synthesized. After determining the electronic and steric properties of these ligands, their properties were compared to those of [Pd(IPr) (cin)Cl]. The three palladium complexes were studied by using DFT calculations to delineate their behavior in the activation step leading to the putative 12-electron active catalyst. Experimentally, their catalytic activity in the Suzuki–Miyaura reaction involving a wide range of coupling partners (30 entries) at low catalyst loading was studied.
- Izquierdo, Frédéric,Zinser, Caroline,Minenkov, Yury,Cordes, David B.,Slawin, Alexandra M. Z.,Cavallo, Luigi,Nahra, Fady,Cazin, Catherine S. J.,Nolan, Steven P.
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- Reversible luminescence "off-on" regulation based on tunable photodimerization: Via crystal-to-cocrystal transformation
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The photophysical properties of organic solid-state materials are inextricably linked to the molecular structures and packing modes. However, it is still a challenge to accurately tune the fluorescence color or on-off regulation of an organic material at
- Jiang, Shimei,Li, Bao,Shang, Hongxing,Wang, Yufei
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supporting information
p. 734 - 741
(2022/01/22)
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- Desulfonative Suzuki–Miyaura Coupling of Sulfonyl Fluorides
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Sulfonyl fluorides have emerged as powerful “click” electrophiles to access sulfonylated derivatives. Yet, they are relatively inert towards C?C bond forming transformations, notably under transition-metal catalysis. Here, we describe conditions under which aryl sulfonyl fluorides act as electrophiles for the Pd-catalyzed Suzuki–Miyaura cross-coupling. This desulfonative cross-coupling occurs selectively in the absence of base and, unusually, even in the presence of strong acids. Divergent one-step syntheses of two analogues of bioactive compounds showcase the expanded reactivity of sulfonyl fluorides to encompass both S?Nu and C?C bond formation. Mechanistic experiments and DFT calculations suggest oxidative addition occurs at the C?S bond followed by desulfonation to form a Pd-F intermediate that facilitates transmetalation.
- Bahadori, Maryam,Brykczyńska, Daria,Chatelain, Paul,Moran, Joseph,Muller, Cyprien,Rowley, Christopher N.,Sau, Abhijit
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supporting information
p. 25307 - 25312
(2021/10/25)
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- Scalable Negishi Coupling between Organozinc Compounds and (Hetero)Aryl Bromides under Aerobic Conditions when using Bulk Water or Deep Eutectic Solvents with no Additional Ligands
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Pd-catalyzed Negishi cross-coupling reactions between organozinc compounds and (hetero)aryl bromides have been reported when using bulk water as the reaction medium in the presence of NaCl or the biodegradable choline chloride/urea eutectic mixture. Both C(sp3)-C(sp2) and C(sp2)-C(sp2) couplings have been found to proceed smoothly, with high chemoselectivity, under mild conditions (room temperature or 60 °C) in air, and in competition with protonolysis. Additional benefits include very short reaction times (20 s), good to excellent yields (up to 98 %), wide substrate scope, and the tolerance of a variety of functional groups. The proposed novel protocol is scalable, and the practicability of the method is further highlighted by an easy recycling of both the catalyst and the eutectic mixture or water.
- Dilauro, Giuseppe,Azzollini, Claudia S.,Vitale, Paola,Salomone, Antonio,Perna, Filippo M.,Capriati, Vito
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supporting information
p. 10632 - 10636
(2021/04/09)
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- N-SUBSTITUTED-3,4-(FUSED 5-RING)-5-PHENYL-PYRROLIDINE-2-ONE COMPOUNDS AS INHIBITORS OF ISOQC AND/OR QC ENZYME
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The present invention pertains generally to the field of therapeutic compounds. More specifically the present invention pertains to certain N-substituted-3,4-(fused 5-ring)-5-phenyl-pyrrolidin-2-one compounds (also referred to herein as "FRPPO compounds"), that, inter alia, inhibit glutaminyl-peptide cyclotransferase-like (isoQC) enzyme and/or glutaminyl-peptide cyclotransferase (QC) enzyme (e.g., inhibit or reduce or block the activity or function of isoQC and/or QC enzyme). The present invention also pertains to pharmaceutical compositions comprising such compounds, and the use of such compounds and compositions, both in vitro and in vivo, to inhibit isoQC and/or QC enzyme; to treat disorders that are ameliorated by the inhibition of isoQC and/or QC enzyme; to treat cancer, atherosclerosis, fibrotic diseases, infectious diseases, Alzheimer's disease, etc.
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(2021/02/12)
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- PYRROLIDINE GLYCOSIDASE INHIBITORS
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Compounds of formula (I) wherein A, W, R3b, Z and p have the meaning according to the claims can be employed, inter alia, for the treatment of tauopathies and Alzheimer's disease.
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Page/Page column 142-143
(2020/03/15)
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- Enabling Catalytic Arene C-H Amidomethylation via Bis(tosylamido)methane as a Sustainable Formaldimine Releaser
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Addition of catalytic arene C-H to formaldimines has been enabled by Ru(II)-catalyzed amidomethylation with bis(tosylamido)methane as a catalytic formaldimine releaser. The new process provides an atom-efficient and sustainable solution to address the challenges of formaldimines in this type of transformation. Furthermore, new synthetic routes based on this catalytic system have been developed for step-efficient access to N-heterotricyclic core structures that are pharmaceutically relevant.
- Li, Zhong-Yuan,Chaminda Lakmal, Hetti Handi,Cui, Xin
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supporting information
p. 3735 - 3740
(2019/05/24)
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- ATAZANAVIR (ATV) ANALOGUES FOR TREATING HIV INFECTIONS
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The invention provides a compound of Formula I: or a pharmaceutically acceptable salt thereof as described herein. The invention also provides pharmaceutical compositions comprising a compound of Formula I, processes for preparing compounds of Formula I, the compound of formula (I) for use in therapeutic methods for treating the proliferation of the HIV virus, treating AIDS or delaying the onset of AIDS symptoms in a mammal using compounds of Formula I. Preferred compounds are N-[(2S) -1-[2-[(2S,3S)-2-hydroxy-3-[[(2S)-2-(methoxycarbonylamino) -3,3-dimethylbutanoyl]amino]-4-phenylbutyl]-2-[(phenyl) methyl]hydrazinyl]-3,3-dimethyl-1-oxobutan-2-yl]carbamate atazanavir (ATV) analogues substituted by several heterocycles, such as e.g. pyrazole (Rl); e.g. oxetane (substituent of X2); e.g. pyridine or pyrimidine (X1); e.g. piperazine or 3,8-diazabicyclo[3.2.1]octan (X2).
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Page/Page column 78; 79; 82; 83
(2018/08/26)
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- Towards environmentally friendlier Suzuki-Miyaura reactions with precursors of Pd-NHC (NHC = N-heterocyclic carbene) complexes
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The preparation of [NHC·H][Pd(η3-R-allyl)Cl2] complexes is disclosed and represents a facile, atom-economical, environmentally friendly and rapid synthesis. These palladates are immediate synthetic precursors to the well-known [Pd(NHC)(η3-R-allyl)Cl] complexes. Their activation leading to catalytically relevant species has been studied in the Suzuki-Miyaura reaction. The need for an activation step prior to the catalysis was examined. The reaction scope showcases its ease and breadth in terms of functional group tolerance. Electron-donating and electron-withdrawing aryl chlorides and bromides were coupled effectively as well as heteroatom-containing and sterically hindered aryl halides. The catalytic reaction was conducted in ethanol with a weak and inexpensive inorganic base.
- Zinser, Caroline M.,Warren, Katie G.,Meadows, Rebecca E.,Nahra, Fady,Al-Majid, Abdullah M.,Barakat, Assem,Islam, Mohammad S.,Nolan, Steven P.,Cazin, Catherine S. J.
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supporting information
p. 3246 - 3252
(2018/07/29)
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- A phosphorescence iridium complex synthesis and its used for cercarian fluorescence-labeled
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The invention belongs to the field of photobiology labeling for preventing and treating parasitic diseases, and relates to synthesis of a phosphorescent iridium complex and the purpose of the phosphorescent iridium complex for the fluorescence labeling of
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Paragraph 0047
(2018/01/11)
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- Chemoselective Synthesis of Polysubstituted Pyridines from Heteroaryl Fluorosulfates
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A selection of heteroaryl fluorosulfates were readily synthesized using commercial SO2F2 gas. These substrates are highly efficient coupling partners in the Suzuki reaction. Through judicious selection of Pd catalysts the fluorosulfate functionality is differentiated from bromide and chloride; the order of reactivity being: -Br> -OSO2F> -Cl. Exploiting this trend allowed the stepwise chemoselective synthesis of a number of polysubstituted pyridines, including the drug Etoricoxib. A selection of heteroaryl fluorosulfates were readily synthesized using commercial SO2F2 gas. These substrates are highly efficient coupling partners in the Suzuki reaction. Through judicious selection of Pd catalysts the fluorosulfate functionality is differentiated from bromide and chloride; the order of reactivity being: -Br> -OSO2F> -Cl. Exploiting this trend allowed the stepwise chemoselective synthesis of a number of polysubstituted pyridines, including the drug Etoricoxib.
- Zhang, Enxuan,Tang, Jiaze,Li, Suhua,Wu, Peng,Moses, John E.,Sharpless, K. Barry
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supporting information
p. 5692 - 5697
(2016/04/20)
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- Comparative Catalytic Activity of Group 9 [CpMIII] Complexes: Cobalt-Catalyzed C-H Amidation of Arenes with Dioxazolones as Amidating Reagents
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A procedure for the [CpCoIII]-catalyzed direct C-H amidation of arenes with dioxazolone has been developed. This reaction proceeds under straightforward and mild conditions with a broad range of substrates, including anilides. A comparative study on the catalytic activity of Group 9 [{CpMCl2}2] complexes revealed the unique efficiency of the cobalt catalyst. Pick of the bunch: A variety of arenes, including anilides, underwent direct C-H amidation with dioxazolones in the presence of a cobalt catalyst with a Cp? ligand under mild and straightforward reaction conditions (see scheme; Piv=pivaloyl). A comparative study of Group 9 [CpMIII] complexes revealed the unique ability of the cobalt catalyst to promote this transformation efficiently.
- Park, Juhyeon,Chang, Sukbok
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supporting information
p. 14103 - 14107
(2016/01/25)
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- Synthesis and biological evaluation of Hydrazone derivatives as antifungal agents
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Emerging yeasts are among the most prevalent causes of systemic infections with high mortality rates and there is an urgent need to develop specific, effective and non-Toxic antifungal agents to respond to this issue. In this study 35 aldehydes, hydrazones and hydrazines were obtained and their antifungal activity was evaluated against Candida species (C. parapsilosis, C.Tropicalis, C. krusei, C. albicans, C. glabrata and C. lusitaneae) and Trichosporon asahii, in an in vitro screening. The minimum inhibitory concentrations (MICs) of the active compounds in the screening was determined against 10 clinical isolates of C. parapsilosis and 10 of T. asahii. The compounds 4-pyridin-2-ylbenzaldehyde] (13a) and tert-butyl-(2Z)-2-(3,4,5-Trihydroxybenzylidine)hydrazine carboxylate (7b) showed the most promising MIC values in the range of 16-32 μg/mL and 8-16 μg/mL, respectively. The compounds' action on the stability of the cell membrane and cell wall was evaluated, which suggested the action of the compounds on the fungal cell membrane. Cell viability of leukocytes and an alkaline comet assay were performed to evaluate the cytotoxicity. Compound 13a was not cytotoxic at the active concentrations. These results support the discovery of promising candidates for the development of new antifungal agents.
- Casanova, Bruna B.,Muniz, Mauro N.,De Oliveira, Thayse,De Oliveira, Luís Flavio,Machado, Michel M.,Fuentefria, Alexandre M.,Gosmann, Grace,Gnoatto, Simone C. B.
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p. 9229 - 9241
(2016/08/31)
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- Contrasting Anticancer Activity of Half-Sandwich Iridium(III) Complexes Bearing Functionally Diverse 2-Phenylpyridine Ligands
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We report the synthesis, characterization, and antiproliferative activity of 15 iridium(III) half-sandwich complexes of the type [(η5-Cp?)Ir(2-(R′-phenyl)-R-pyridine)Cl] bearing either an electron-donating (-OH, -CH2OH, -CH3) or electron-withdrawing (-F, -CHO, -NO2) group at various positions on the 2-phenylpyridine (2-PhPy) chelating ligand giving rise to six sets of structural isomers. The X-ray crystal structures of [(η5-Cp?)Ir(2-(2′-fluorophenyl)pyridine)Cl] (1) and [(η5-Cp?)Ir(2-(4′-fluorophenyl)pyridine)Cl] (2) exhibit the expected "piano-stool" configuration. DFT calculations showed that substituents caused only localized effects on the electrostatic potential surface of the chelating 2-PhPy ligand of the complexes. Hydrolysis of all complexes is rapid, but readily reversed by addition of NaCl. The complexes show preferential binding to 9-ethylguanine over 9-methyladenine and are active catalysts for the oxidation of NADH to NAD+. Antiproliferative activity experiments in A2780 ovarian, MCF-7 breast, A549 lung, and HCT116 colon cancer cell lines showed IC50 values ranging from 1 to 89 μM, with the most potent complex, [(η5-Cp?)Ir(2-(2′-methylphenyl)pyridine)Cl] (13) (A2780 IC50 = 1.18 μM), being 10× more active than the parent, [(η5-Cp?)Ir(2-phenylpyridine)Cl], and 2× more active than [(η5-CpxPh)Ir(2-phenylpyridine)Cl]. Intriguingly, contrasting biological activities are observed between structural isomers despite exhibiting similar chemical reactivity. For pairs of structural isomers both the nature and position of the functional group can affect the hydrophobicity of the complex. An increase in hydrophobicity resulted in enhanced cellular-iridium accumulation in A2780 ovarian cells, which generally gave rise to an increase in potency. The structural isomers [(η5-Cp?)Ir(2-(4′-fluorophenyl)pyridine)Cl] (2) and [(η5-Cp?)Ir(2-phenyl-5-fluoropyridine)Cl] (4) preferentially localized in the cytosol > membrane and particulate > nucleus > cytoskeleton. This work highlights the strong dependence of biological behavior on the nature and position of the substituent on the chelating ligand and shows how this class of organometallic anticancer complexes can be fine-tuned to increase their potency without using extended cyclopentadienyl systems. (Chemical Equation Presented).
- Millett, Adam J.,Habtemariam, Abraha,Romero-Canelón, Isolda,Clarkson, Guy J.,Sadler, Peter J.
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supporting information
p. 2683 - 2694
(2015/06/23)
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- Cobalt(III)-Catalyzed Directed C-H Coupling with Diazo Compounds: Straightforward Access towards Extended π-Systems
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The first highly efficient and scalable cobalt-catalyzed directed C-H functionalization with carbene precursors is presented. This methodology provides a modular route towards a new class of conjugated polycyclic hydrocarbons with tunable emission wavelengths both in solution and in the solid state.
- Zhao, Dongbing,Kim, Ju Hyun,Stegemann, Linda,Strassert, Cristian A.,Glorius, Frank
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supporting information
p. 4508 - 4511
(2015/04/14)
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- Copper acetate-DMSO promoted methylthiolation of arenes and heteroarenes
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An unprecedented copper acetate-DMSO promoted methylthiolation of arenes and heteroarenes in the presence of air has been developed. The reaction is highly regioselective under the directing group influence of pyridine and pyrimidine functional units and gives the thiomethylated product in moderate to high yields.
- Sharma, Poonam,Rohilla, Sandeep,Jain, Nidhi
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p. 4116 - 4122
(2015/05/05)
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- Ruthenium-Catalyzed meta-Selective C-H Bromination
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The first example of a transition-metal-catalyzed, meta-selective C-H bromination procedure is reported. In the presence of catalytic [{Ru(p-cymene)Cl2}2], tetrabutylammonium tribromide can be used to functionalize the meta C-H bond of 2-phenylpyridine derivatives, thus affording difficult to access products which are highly predisposed to further derivatization. We demonstrate this utility with one-pot bromination/arylation and bromination/alkenylation procedures to deliver meta-arylated and meta-alkenylated products, respectively, in a single step. Taking position: 2-Phenylpyridines undergo meta-selective bromination using tetrabutylammonium tribromide under ruthenium catalysis, thus affording products that are highly predisposed to further derivatization. The bromination can be combined with arylation and alkenylation chemistry to access meta-arylated and meta-alkenylated products, respectively, in a one-pot operation.
- Teskey, Christopher J.,Lui, Andrew Y. W.,Greaney, Michael F.
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supporting information
p. 11677 - 11680
(2015/10/05)
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- Complete Switch of Selectivity in the C-H Alkenylation and Hydroarylation Catalyzed by Iridium: The Role of Directing Groups
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A complete switch in the CpIr(III)-catalyzed paths between C-H olefination and hydroarylation was found to be crucially dependent on the type of directing groups. This dichotomy in product distribution was correlated to the efficiency in attaining syn-coplanarity of olefin-inserted 7-membered iridacycles. Theoretical studies support our hypothesis that the degree of flexibility of this key intermediate modulates the β-H elimination, which ultimately affords the observed chemoselectivity.
- Kim, Jiyu,Park, Sung-Woo,Baik, Mu-Hyun,Chang, Sukbok
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supporting information
p. 13448 - 13451
(2015/11/09)
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- Synthesis, crystal structures and catalytic activity of three cyclopalladated 6-bromo-2-ferrocenylquinoline complexes with N-heterocyclic carbenes (NHCs) and triphenylphosphine
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Three cyclopalladated 6-bromo-2-ferrocenylquinoline complexes with NHCs and PPh3 1-3 have been synthesized and characterized by elemental analysis, IR, NMR and single-crystal X-ray diffraction. Their application to Suzuki coupling of phenylboro
- Xu, Chen,Li, Hong-Mei,Wang, Zhi-Qiang,Fu, Wei-Jun
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- Synthesis, crystal structures and catalytic activity of three cyclopalladated 6-bromo-2-ferrocenylquinoline complexes with N-heterocyclic carbenes (NHCs) and triphenylphosphine
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Three cyclopalladated 6-bromo-2-ferrocenylquinoline complexes with NHCs and PPh3 1-3 have been synthesized and characterized by elemental analysis, IR, NMR and single-crystal X-ray diffraction. Their application to Suzuki coupling of phenylboronic acid co
- Xu, Chen,Li, Hong-Mei,Wang, Zhi-Qiang,Fu, Wei-Jun
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- Synthesis, crystal structures and catalytic activity of three cyclopalladated 6-bromo-2-ferrocenylquinoline complexes with N-heterocyclic carbenes (NHCs) and triphenylphosphine
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Three cyclopalladated 6-bromo-2-ferrocenylquinoline complexes with NHCs and PPh31-3 have been synthesized and characterized by elemental analysis, IR, NMR and single-crystal X-ray diffraction. Their application to Suzuki coupling of phenylboron
- Xu, Chen,Li, Hong-Mei,Wang, Zhi-Qiang,Fu, Wei-Jun
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- General suzuki coupling of heteroaryl bromides by using tri-tert-butylphosphine as a supporting ligand
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A general procedure for the fast Suzuki coupling of major families of heteroaryl bromides was realized by using Pd(OAc)2/PtBu3 as the catalyst. Many couplings were finished within minutes at room temperature in n-butanol. Different from previous studies, three typical heteroaryl bromides were systematically examined in couplings of various heteroaryl and aryl boronic acids. A fast, general coupling of heteroaryl bromides is realized by using a single palladium catalyst supported by tri-tert-butylphosphine.
- Zou, Yinjun,Yue, Guizhou,Xu, Jianwei,Zhou, Jianrong
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supporting information
p. 5901 - 5905
(2015/03/30)
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- Orthogonal reactivity of acyl azides in C-H activation: Dichotomy between C-C and C-N amidations based on catalyst systems
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The dual reactivity of acyl azides was utilized successfully in C-H activation by the choice of catalyst systems: while selective C-C amidation was achieved under thermal Rh catalysis, a Ru catalyst was found to mediate direct C-N amidation also highly se
- Shin, Kwangmin,Ryu, Jaeyune,Chang, Sukbok
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supporting information
p. 2022 - 2025
(2014/05/06)
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- Palladium-catalyzed trifluoromethylthiolation of aryl C-H bonds
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A method for monotrifluoromethylthiolation of arenes via palladium-catalyzed directed C-H bond activation was described. The reaction was compatible with a variety of functional groups. Initial mechanistic studies disclosed that the turnover limiting step of the catalytic cycle did not involve C-H activation.
- Xu, Chunfa,Shen, Qilong
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supporting information
p. 2046 - 2049
(2014/05/06)
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- Cu-catalyzed direct amidation of aromatic C-H bonds: An access to arylamines
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A Cu-catalyzed aromatic C-H amidation with phthalimide under oxygen as a terminal oxidant without using additional additives has been achieved. This reaction has the broad substrate scope and shows moderate to good yields in most cases. This method is complementary to the previously reported metal-catalyzed C-H amination systems.
- Xu, Hui,Qiao, Xixue,Yang, Shiping,Shen, Zengming
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p. 4414 - 4422
(2014/06/09)
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- N -substituted hydroxylamines as synthetically versatile amino sources in the iridium-catalyzed mild C-H amidation reaction
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N-Substituted hydroxylamines such as aroyloxy- or acyloxycarbamates were successfully employed as synthetically versatile amino precursors in the iridium-catalyzed direct C-H amidation of arenes. The reaction proceeds smoothly at room temperature over a broad range of substrates with high functional group tolerance to afford N-substituted arylamine products.
- Patel, Pitambar,Chang, Sukbok
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supporting information
p. 3328 - 3331
(2014/07/08)
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- A general catalyst for Suzuki-Miyaura and Sonogashira reactions of aryl and heteroaryl chlorides in water
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We report the synthesis of 2-(3-sulfonatomesityl)-5-sulfonatoindenyl) dicyclohexylphosphine hydrate sodium salt and its use in palladium-catalyzed Suzuki-Miyaura and Sonogashira coupling reactions in water (and biphasic water-organic solvent mixtures) to prepare a variety of functionalized biaryls and aryl alkynes in excellent yield. This journal is the Partner Organisations 2014.
- Peng, Hui,Chen, Ya-Qin,Mao, Shu-Lan,Pi, Yun-Xiao,Chen, You,Lian, Ze-Yu,Meng, Tong,Liu, Sheng-Hua,Yu, Guang-Ao
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supporting information
p. 6944 - 6952
(2014/09/29)
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- Synthesis and properties of a dendritic FRET donor-acceptor system with cationic iridium(iii) complex core and carbazolyl periphery
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In order to enhance the photoluminescence of cyclometalated iridium(iii) complexes, which are potentially useful for biolabeling and bioimaging, a series of benzyl ether branched dendritic moieties with carbazolyl termini were introduced to the cyclometal
- Li, Yanfang,Liu, Yang,Zhou, Ming
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p. 2582 - 2591
(2012/05/04)
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- Negishi coupling of 2-pyridylzinc bromide-paradigm shift in cross-coupling chemistry?
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The efficient cross-coupling of 2-pyridylzinc bromide with functionalized aryl halides has been accomplished by a simple and highly efficient protocol. To the best of our knowledge, we report the first shelf life study of 2-pyridylzinc bromide which confirms the excellent stability of this compound and underlines the synthetic value of organozinc reagents in the cross-coupling reactions of sensitive heterocyclic nucleophiles on academic and commercial scale.
- Coleridge, Brian M.,Bello, Charles S.,Ellenberger, David H.,Leitner, Andreas
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experimental part
p. 357 - 359
(2010/03/24)
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- PROCESS FOR THE PREPARATION OF ARYLPYRIDINYL COMPOUNDS
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A process is described for the preparation of arylpyridine compounds by aryl-aryl cross-coupling reactions between a halopyridine and an arylmagnesium halide carried out in the presence of a catalytic amount of a zinc salt and a catalytic amount of palladium complex with a bidentate phosphine. The zinc salt is preferably selected from ZnCl2, ZnBr2 and/or Zn(OAc)2, while the palladium complex with a bidentate phosphine is preferably selected from the group of (1,2-Bis(diphenylphosphino)ethane)palladium(II) chloride, (1,3-Bis(diphenylphosphino)propane) palladium(II) chloride and (1,4-Bis(diphenylphosphino)butane)palladium(II) chloride. Most preferred is (1,2-Bis(diphenylphosphino)ethane)palladium(II) chloride. It is thus possible to obtain molar yields higher than 95% calculated on the arylmagnesium halide and a catalyticity less than 1 : 1500. The process is particularly suitable for the preparation of 4-(2'-pyridyl)benzaldehyde which can then effectively been converted to N1-(t-butoxycarbonyl)-N2-(4-(2'pyridyl)benzyl)hydrazine.
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Page/Page column 14
(2011/01/12)
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- An efficient and practical synthesis of the HIV protease inhibitor atazanavir via a highly diastereoselective reduction approach
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An efficient and practical synthesis of the HIV-1 protease inhibitor Atazanavir was developed by employing the diastereoselective reduction of ketomethylene aza-dipeptide isostere 10 as the key and final step. The high diastereoselectivity of the amino ketone reduction by lithium tri-iert-butoxyaluminum hydride in diethyl ether to afford the desired svn-1,2-amino alcohol structure was achieved by Felkin- Anh control as a result of the bulky and chiral N-(methoxycarbonyl)-L-tert-leucinyl moiety as the nitrogen protecting group. The coupling of the two key intermediates, N-(methoxycarbonyl)-L-tert-leucine acylated benzyl hydrazine 7 and chloromethyl ketone 9, via an SN2 reaction furnished the amino ketone 10 in high yield under our optimized conditions. Our new methodology features the late introduction of the S-hydroxyl group and the early acylation of benzyl hydrazine and chloromethyl ketone with N-(methoxycarbonyl)-L-tert-leucine, respectively, which confers high efficiency and easy purification.
- Fan, Xing,Song, Yan-Li,Long, Ya-Qiu
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- Practical routes to 2,6-disubstituted pyridine derivatives
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We report the synthesis of a series of 2,6-disubstituted pyridines in a straightforward manner starting from readily available 2-substituted pyridines. The main sequence involves a selective ?-lithiation reaction with halogen functionalization followed by
- Vandromme, Lucie,Reissig, Hans-Ulrich,Groeper, Susie,Rabe, Juergen P.
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experimental part
p. 2049 - 2055
(2009/04/04)
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- Methods of treatment using an EP2 selective receptor agonist
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The present invention relates to methods of treating pulmonary hypertension, facilitating joint fusion, facilitating tendon and ligament repair, reducing the occurrence of secondary fracture, treating avascular necrosis, facilitating cartilage repair, facilitating bone healing after limb transplantation, facilitating liver regeneration, facilitating wound healing, reducing the occurrence of gastric ulceration, treating hypertension, facilitating the growth of tooth enamel or finger or toe nails, treating glaucoma, treating ocular hypertension, and repairing damage caused by metastatic bone disease using an EP2 selective receptor agonist.
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Page/Page column 48
(2010/02/13)
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- Biarylcarboxybenzamide derivatives as potent vanilloid receptor (VR1) antagonistic ligands
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Seventeen biarylcarboxybenzamide derivatives were prepared for the study of their agonistic/antagonistic activities to the vanilloid receptor (VR1) in rat DRG neurons. The replacement of the piperazine moiety of the lead compound 1 with phenyl ring showed quite enhanced antagonistic activity. Among the prepared derivatives, N-(4-tert-butylphenyl)-4-pyridine-2-yl-benzamide (2, IC 50 = 31 nM) and N-(4-tert-butylphenyl)-4-(3-methylpyridine-2-yl) benzamide (3g, IC50 = 31 nM), showed 5-fold higher antagonistic activity than 1 in 45Ca2+-influx assay.
- Park, Hyeung-Geun,Choi, Ji-Yeon,Kim, Mi-Hyun,Choi, Sea-Hoon,Park, Mi-Kyung,Lee, Jihye,Suh, Young-Ger,Cho, Hawon,Oh, Uhtaek,Kim, Hee-Doo,Joo, Yung Hyup,Shin, Song Seok,Kim, Jin Kwan,Jeong, Yeon Su,Koh, Hyun-Ju,Park, Young-Ho,Jew, Sang-Sup
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p. 631 - 634
(2007/10/03)
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- Process for the preparation of aryl-pyridinyl compounds
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A process is described for the preparation of arylpyridine compounds by aryl-aryl cross-coupling reactions between a halopyridine and an arylmagnesium halide carried out in the presence of a catalytic amount of a zinc salt and a catalytic amount of palladium. The zinc salt is preferably selected from ZnCl2, ZnBr2 and/or Zn(OAc)2, while the palladium is preferably used in the form of Pd(PPh3)4 or Pd(OAc)2 +4 PPh3. The reaction can also be carried out in the presence of bidentate phosphines, such as, for example, 1,3-bis(diphenylphosphine)propane or 1,4-bis(diphenylphosphine)-butane. It is thus possible to obtain molar yields higher than 97% (calculated relative to the halopyridine) and a catalyticity of more than 2000.
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Page column 9
(2010/02/07)
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- Synthesis of novel palladacycles and their application in heck and Suzuki reactions under aerobic conditions
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(Chemical Equation Presented) Design and synthesis of a novel family of furancarbothioamide-based palladacycles are reported herein. These palladacycles are thermally stable, not sensitive to air or moisture, and are applied effectively in the Heck reaction of aryl halides with terminal olefins and in the Suzuki reaction of aryl halides with arylboronic acids. These reactions were performed under aerobic conditions, leading to turnover numbers (TONs) up to 1 × 105.
- Xiong, Zhengchang,Wang, Nengdong,Dai, Mingji,Li, Ang,Chen, Jiahua,Yang, Zhen
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p. 3337 - 3340
(2007/10/03)
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- Application of the lewis acid-lewis base bifunctional asymmetric catalysts to pharmaceutical syntheses: Stereoselective chiral building block syntheses of human immunodeficiency virus (HIV) protease inhibitor and β3- adenergic receptor agonist
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Chiral building block syntheses of promising drugs were achieved using two types of catalytic stereoselective cyanosilylations of aldehydes promoted by Lewis acid-Lewis base bifunctional catalysts 1 and 2 as the key steps (diastereoselective cyanosilylation of amino aldehyde and enantioselective cyanosilylation). In the first part of this article, syntheses of chiral building blocks (6) of Atazanavir (3: human immunodeficiency virus (HIV) protease inhibitor) using the bifunctional catalyst 2 are discussed. The reaction of Boc-protected phenylalaninal 21 in the presence of 1 mol% catalyst 2 selectively afforded the anti isomer 22 as the major product (diastereomeric ratio=97:3), which was successively converted to the corresponding epoxide 6 in six steps. In the second part, we describe a chiral building block synthesis of β3-adrenergic receptor agonists. The enantioselective cyanosilylation of 3-chlorobenzaldehyde (38) with 9 mol% catalyst 1 gave the chiral cyanohydrin 39, which was converted to β-hydroxyethylamine 40 by reduction. Moreover, the chiral ligand of catalyst 1 could be recovered without column chromatography and reused without decreasing its activity.
- Nogami, Hiroyuki,Kanai, Motomu,Shibasaki, Masakatsu
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p. 702 - 709
(2007/10/03)
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- Method for treating glaucoma
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Methods of using prostaglandin agonists for the reduction of intraocular pressure, and accordingly glaucoma.
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- Prostaglandin agonists and their use to treat bone disorders
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This invention relates to prostaglandin agonists, methods of using such prostaglandin agonists, pharmaceutical compositions containing such prostaglandin agonists and kits containing such prostaglandin agonists. The prostaglandin agonists are useful for the treatment of bone disorders including osteoporosis.
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- Process research and development for an efficient synthesis of the HIV protease inhibitor BMS-232632
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Development of an efficient and scalable process for the human immunodeficiency virus (HIV) protease inhibitor BMS-232632 1-[4-(pyridin-2-yl)phenyl]-5(S)-2,5-bis{[N-(methoxycarbonyl)L-tert- leucinyl]-amino}-4(S)-hydroxy-6-phenyl-2-azahexane, is described. The key step in the synthesis of the intermediate N-1-(tert-butyloxycarbonyl)-N-2-[4-(pyridin-2-yl)benzylidene]hydrazone (11) was the Pd-mediated coupling of boronic acid 9 with 2-bromopyridine. An efficient procedure was developed for the chemoselective reduction of hydrazone 11 to hydrazine carbamate 4. The key intermediate N-(tert-butyloxycarbonyl)-2(S)-amino-1-phenyl-3(R)-3,4-epoxy-butane (6) was prepared stereoselectively from chiral diol 10. The subsequent union of 4 and 6 followed by coupling with N-methoxycarbonyl-L-tert-leucine provided the free base BMS-232632 in high yield. Evaluation of a variety of salts and identification of bisulfate salt 19 with enhanced bioavallability are also described.
- Xu, Zhongmin,Singh, Janak,Schwinden, Mark D.,Zheng, Bin,Kissick, Thomas P.,Patel, Bharat,Humora, Michael J.,Quiroz, Fernando,Dong, Lin,Hsieh, Dau-Ming,Heikes, James E.,Pudipeddi, Madhusudhan,Lindrud, Mark D.,Srivastava, Sushil K.,Kronenthal, David R.,Mueller, Richard H.
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p. 323 - 328
(2013/09/06)
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- Prevention of loss and restoration of bone mass by certain prostaglandin agonists
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Prostaglandin agonists of formula (I), in which, for example, A is a sulphonyl or acyl group, B is N or CH, M contains a ring and K and Q are linking groups, methods of using such prostaglandin agonists, pharmaceutical compositions containing such prostaglandin agonists and kits useful for the treatment of bone disorders including osteoporosis. STR1
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