- Regiodivergent Reductive Opening of Epoxides by Catalytic Hydrogenation Promoted by a (Cyclopentadienone)iron Complex
-
The reductive opening of epoxides represents an attractive method for the synthesis of alcohols, but its potential application is limited by the use of stoichiometric amounts of metal hydride reducing agents (e.g., LiAlH4). For this reason, the corresponding homogeneous catalytic version with H2 is receiving increasing attention. However, investigation of this alternative has just begun, and several issues are still present, such as the use of noble metals/expensive ligands, high catalytic loading, and poor regioselectivity. Herein, we describe the use of a cheap and easy-To-handle (cyclopentadienone)iron complex (1a), previously developed by some of us, as a precatalyst for the reductive opening of epoxides with H2. While aryl epoxides smoothly reacted to afford linear alcohols, aliphatic epoxides turned out to be particularly challenging, requiring the presence of a Lewis acid cocatalyst. Remarkably, we found that it is possible to steer the regioselectivity with a careful choice of Lewis acid. A series of deuterium labeling and computational studies were run to investigate the reaction mechanism, which seems to involve more than a single pathway.
- Tadiello, Laura,Gandini, Tommaso,Stadler, Bernhard M.,Tin, Sergey,Jiao, Haijun,de Vries, Johannes G.,Pignataro, Luca,Gennari, Cesare
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p. 235 - 246
(2022/01/03)
-
- Chemoselective Cleavage of Si-C(sp3) Bonds in Unactivated Tetraalkylsilanes Using Iodine Tris(trifluoroacetate)
-
Organosilanes are synthetically useful reagents and precursors in organic chemistry. However, the typical inertness of unactivated Si-C(sp3) bonds under conventional reaction conditions has hampered the application of simple tetraalkylsilanes in organic synthesis. Herein we report the chemoselective cleavage of Si-C(sp3) bonds of unactivated tetraalkylsilanes using iodine tris(trifluoroacetate). The reaction proceeds smoothly under mild conditions (-50 °C to room temperature) and tolerates various polar functional groups, thus enabling subsequent Tamao-Fleming oxidation to provide the corresponding alcohols. NMR experiments and density functional theory calculations on the reaction indicate that the transfer of alkyl groups from Si to the I(III) center and the formation of the Si-O bond proceed concertedly to afford an alkyl-λ3-iodane and silyl trifluoroacetate. The developed method enables the use of unactivated tetraalkylsilanes as highly stable synthetic precursors.
- Matsuoka, Keitaro,Komami, Narumi,Kojima, Masahiro,Mita, Tsuyoshi,Suzuki, Kimichi,Maeda, Satoshi,Yoshino, Tatsuhiko,Matsunaga, Shigeki
-
supporting information
p. 103 - 108
(2021/01/13)
-
- Borane evolution and its application to organic synthesis using the phase-vanishing method
-
Although borane is a useful reagent, it is difficult to handle. In this study, borane was generated in situ from NaBH4 or nBu4NBH4 with several oxidants using a phase-vanishing (PV) method. The borane generated was directly reacted with alkenes, affording the desired alcohols in good yields after oxidation with H2O2 under basic conditions. The selective reduction of carboxylic acids with the evolved borane was examined. The organoboranes generated by the PV method successfully underwent Suzuki–Miyaura coupling. Using this PV system, reactions with borane can be carried out easily and safely in a common test tube.
- Soga, Nene,Yoshiki, Tomo,Sato, Aoi,Kawamoto, Takuji,Ryu, Ilhyong,Matsubara, Hiroshi
-
supporting information
(2021/03/26)
-
- Structure-Activity Relationship Explorations and Discovery of a Potent Antagonist for the Free Fatty Acid Receptor 2
-
Free fatty acid receptor 2 (FFA2) is a sensor for short-chain fatty acids that has been identified as an interesting potential drug target for treatment of metabolic and inflammatory diseases. Although several ligand series are known for the receptor, the
- H?jgaard Hansen, Anders,Christensen, Henriette B.,Pandey, Sunil K.,Sergeev, Eugenia,Valentini, Alice,Dunlop, Julia,Dedeo, Domonkos,Fratta, Simone,Hudson, Brian D.,Milligan, Graeme,Ulven, Trond,Rexen Ulven, Elisabeth
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p. 3326 - 3341
(2021/09/14)
-
- Erbium-Catalyzed Regioselective Isomerization-Cobalt-Catalyzed Transfer Hydrogenation Sequence for the Synthesis of Anti-Markovnikov Alcohols from Epoxides under Mild Conditions
-
Herein, we report an efficient isomerization-transfer hydrogenation reaction sequence based on a cobalt pincer catalyst (1 mol %), which allows the synthesis of a series of anti-Markovnikov alcohols from terminal and internal epoxides under mild reaction conditions (≤55 °C, 8 h) at low catalyst loading. The reaction proceeds by Lewis acid (3 mol % Er(OTf)3)-catalyzed epoxide isomerization and subsequent cobalt-catalyzed transfer hydrogenation using ammonia borane as the hydrogen source. The general applicability of this methodology is highlighted by the synthesis of 43 alcohols from epoxides. A variety of terminal (23 examples) and 1,2-disubstituted internal epoxides (14 examples) bearing different functional groups are converted to the desired anti-Markovnikov alcohols in excellent selectivity and yields of up to 98%. For selected examples, it is shown that the reaction can be performed on a preparative scale up to 50 mmol. Notably, the isomerization step proceeds via the most stable carbocation. Thus, the regiochemistry is controlled by stereoelectronic effects. As a result, in some cases, rearrangement of the carbon framework is observed when tri-and tetra-substituted epoxides (6 examples) are converted. A variety of functional groups are tolerated under the reaction conditions even though aldehydes and ketones are also reduced to the respective alcohols under the reaction conditions. Mechanistic studies and control experiments were used to investigate the role of the Lewis acid in the reaction. Besides acting as the catalyst for the epoxide isomerization, the Lewis acid was found to facilitate the dehydrogenation of the hydrogen donor, which enhances the rate of the transfer hydrogenation step. These experiments additionally indicate the direct transfer of hydrogen from the amine borane in the reduction step.
- Liu, Xin,Longwitz, Lars,Spiegelberg, Brian,T?njes, Jan,Beweries, Torsten,Werner, Thomas
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p. 13659 - 13667
(2020/11/30)
-
- Iron-Catalyzed β-Alkylation of Alcohols
-
β-Branched alkylated alcohols have been prepared in good yields using a double-hydrogen autotransfer strategy in the presence of our diaminocyclopentadienone iron tricarbonyl complex Fe1. The alkylation of some 2-arylethanol derivatives was successfully addressed with benzylic alcohols and methanol as alkylating reagents under mild conditions. Deuterium labeling experiments suggested that both alcohols (2-arylethanol and either methanol or benzyl alcohol) served as hydrogen donors in this cascade process.
- Bettoni, Leó,Gaillard, Sylvain,Renaud, Jean-Luc
-
supporting information
p. 8404 - 8408
(2019/10/16)
-
- Structural hybridization of pyrrolidine-based T-type calcium channel inhibitors and exploration of their analgesic effects in a neuropathic pain model
-
Highly effective and safe drugs for the treatment of neuropathic pain are urgently required and it was shown that blocking T-type calcium channels can be a promising strategy for drug development for neuropathic pain. We have developed pyrrolidine-based T
- Son, Woo Seung,Jeong, Kyu-Sung,Lim, Sang Min,Pae, Ae Nim
-
p. 1168 - 1172
(2019/03/28)
-
- CERAMIDE GALACTOSYLTRANSFERASE INHIBITORS FOR THE TREATMENT OF DISEASE
-
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.
- -
-
Paragraph 00452-00454
(2019/06/11)
-
- SPHINGOSINE KINASE INHIBITOR AMIDOXIME PRODRUGS
-
Sphingosine kinases are enzymes that catalyze the biosynthesis of sphingosine-1-phosphate. The invention provides prodrugs of compounds that are effective for inhibition of sphingosine kinase type 1, sphingosine kinase type 2, or both, according to formula (I) as described herein. Formula I compounds are useful in the treatment of a range of diseases wherein increasing the level of sphingosine-1-phosphate in blood is medically indicated. The invention also provides pharmaceutical compositions of Formula I compounds.
- -
-
Page/Page column 133; 148
(2017/11/03)
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- Anti-Markovnikov alkene oxidation by metal-oxo–mediated enzyme catalysis
-
Catalytic anti-Markovnikov oxidation of alkene feedstocks could simplify synthetic routes to many important molecules and solve a long-standing challenge in chemistry. Here we report the engineering of a cytochrome P450 enzyme by directed evolution to catalyze metal-oxo–mediated anti-Markovnikov oxidation of styrenes with high efficiency. The enzyme uses dioxygen as the terminal oxidant and achieves selectivity for anti-Markovnikov oxidation over the kinetically favored alkene epoxidation by trapping high-energy intermediates and catalyzing an oxo transfer, including an enantioselective 1,2-hydride migration. The anti-Markovnikov oxygenase can be combined with other catalysts in synthetic metabolic pathways to access a variety of challenging anti-Markovnikov functionalization reactions.
- Hammer, Stephan C.,Kubik, Grzegorz,Watkins, Ella,Huang, Shan,Minges, Hannah,Arnold, Frances H.
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p. 215 - 218
(2017/10/19)
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- Regioselective hydrosilylation of epoxides catalysed by nickel(II) hydrido complexes
-
Bench-stable nickel fluoride complexes bearing NNN pincer ligands have been employed as precursors for the regioselective hydrosilylation of epoxides at room temperature. A nickel hydride assisted epoxide opening is followed by the cleavage of the newly formed nickel oxygen bond by σ-bond metathesis with a silane.
- Wenz, Jan,Wadepohl, Hubert,Gade, Lutz H.
-
supporting information
p. 4308 - 4311
(2017/04/21)
-
- Antiproliferative activity and SARs of caffeic acid esters with mono-substituted phenylethanols moiety
-
A series of CAPE derivatives with mono-substituted phenylethanols moiety were synthesized and evaluated by MTT assay on growth of 4 human cancer cell lines (Hela, DU-145, MCF-7 and ECA-109). The substituent effects on the antiproliferative activity were systematically investigated for the first time. It was found that electron-donating and hydrophobic substituents at 2′-position of phenylethanol moiety could significantly enhance CAPE's antiproliferative activity. 2′-Propoxyl derivative, as a novel caffeic acid ester, exhibited exquisite potency (IC50?=?0.4?±?0.02 & 0.6?±?0.03?μM against Hela and DU-145 respectively).
- Xie, Jin,Yang, Fengzhi,Zhang, Man,Lam, Celine,Qiao, Yixue,Xiao, Jia,Zhang, Dongdong,Ge, Yuxuan,Fu, Lei,Xie, Dongsheng
-
p. 131 - 134
(2016/12/27)
-
- SPHINGOSINE KINASE INHIBITORS
-
Sphingosine kinases are enzymes that catalyze the biosynthesis of sphingosine-1-phosphate. The invention provides compounds that are effective for inhibition of sphingosine kinase type 1, sphingosine kinase type 2, or both. Certain compounds are selective for sphingosine kinase type 2 relative to sphingosine kinase type 1. Compounds of the invention can be used in treatment of a range of diseases wherein increasing the level of sphingosine-1-phosphate in blood is medically indicated. Diseases that can be treated by administration of an effective dose of a compound of the invention include a neoplastic disease that involves excess vascular growth; macular degeneration or diabetic retinopathy; an allergic disease such as asthma, an inflammatory disease of the eye such as uveitis, scleritis, or vitritis; an inflammatory disease of the kidney; a fibrotic disease; atherosclerosis; or pulmonary arterial hypertension. A compound of the invention can be used to improve the integrity of a vascular barrier in a disease where the vascular barrier is disrupted, such as cancer or Alzheimer's disease.
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-
Page/Page column 125
(2016/04/26)
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- 3,3-DIFLUORO-PIPERIDINE DERIVATIVES AS NR2B NMDA RECEPTOR ANTAGONISTS
-
Disclosed are chemical entities of Formula (I): wherein X, Y, Z, R1, R3, R4 and R5 are defined herein, as NR2B subtype selective receptor antagonists. Also disclosed are pharmaceutical compositions comprising a chemical entity of Formula (I), and methods of treating various diseases and disorders associated with NR2B antagonism, e.g., diseases and disorders of the CNS, such as depression, by administering a chemical entity of Formula (I).
- -
-
Paragraph 0172
(2016/09/22)
-
- Direct β-Selective Cross-Coupling of Alkenyl Gold Complexes with Alkyl Electrophiles
-
Alkenyl gold complexes are common intermediates in gold-catalyzed transformations of allenes and alkynes, and numerous methods for their functionalization have been explored. Particularly valuable are cross-coupling reactions, which result in the formation of a new C–C bond. Several strategies are known that enable α-selective cross-coupling of alkenyl gold complexes with aryl, allyl, or acyl coupling partners. We describe the direct β-selective cross-coupling of alkenyl gold complexes with simple alkyl electrophiles. We also describe the effects of the steric and electronic properties of alkenyl gold complexes on the selectivity of the cross-coupling reaction.
- Nguyen, Julia,Duncan, Nicole,Lalic, Gojko
-
supporting information
p. 5803 - 5806
(2016/12/18)
-
- One-Carbon Homologation of Primary Alcohols and the Reductive Homologation of Aldehydes Involving a Jocic-Type Reaction
-
(Trichloromethyl)carbinols, which are formed in one operation from either alcohols or aldehydes, can be converted into primary alcohols in a Jocic-type reaction involving LiBH4. The net result is a convenient two-step, one-carbon homologation of primary alcohols or a reductive one-carbon homologation of aldehydes featuring a broad substrate scope. The method is step-economical, and it nicely complements established one-carbon homologation strategies. (Trichloromethyl)carbinols, which are formed in one operation from either alcohols or aldehydes, can be converted into primary alcohols in a Jocic-type reaction involving LiBH4. The net result is a convenient two-step, one-carbon homologation of primary alcohols or a reductive one-carbon homologation of aldehydes featuring a broad substrate scope.
- Li, Zhexi,Gupta, Manoj K.,Snowden, Timothy S.
-
p. 7009 - 7019
(2015/11/16)
-
- Highly efficient and chemoselective zinc-catalyzed hydrosilylation of esters under mild conditions
-
A mild and highly efficient catalytic hydrosilylation protocol for room-temperature ester reductions has been developed using diethylzinc as the catalyst. The methodology is operationally simple, displays high functional group tolerance and provides for a facile access to a broad range of different alcohols in excellent yields.
- Kovalenko, Oleksandr O.,Adolfsson, Hans
-
supporting information
p. 2785 - 2788
(2015/02/05)
-
- FUSED THIOPHENE AND THIAZOLE DERIVATIVES AS ROR GAMMA MODULATORS
-
The present invention provides fused thiophene and thiazole derivatives of formula (I), which may be therapeutically useful, more particularly as RORγ modulators; in which R1, R2, R3, R4, R5, R6, R7, X1, X2, L, m, n and ring A have the meanings given in the specification, and pharmaceutically acceptable salts thereof that are useful in the treatment and prevention of diseases or disorders, in particular their use in disease(s) or disorder(s) where there is an advantage in modulating RORγ receptor. The present invention also provides preparation of the compounds and pharmaceutical formulations comprising at least one of the fused thiophene and thiazole derivatives of formula (I), together with a pharmaceutically acceptable carrier, diluent or excipient therefor.
- -
-
Page/Page column 127;
(2015/07/16)
-
- Highly chemoselective reduction of amides (primary, secondary, tertiary) to alcohols using SmI2/amine/H2O under mild conditions
-
Highly chemoselective direct reduction of primary, secondary, and tertiary amides to alcohols using SmI2/amine/H2O is reported. The reaction proceeds with C-N bond cleavage in the carbinolamine intermediate, shows excellent functional group tolerance, and delivers the alcohol products in very high yields. The expected C-O cleavage products are not formed under the reaction conditions. The observed reactivity is opposite to the electrophilicity of polar carbonyl groups resulting from the nX → πC=O (X = O, N) conjugation. Mechanistic studies suggest that coordination of Sm to the carbonyl and then to Lewis basic nitrogen in the tetrahedral intermediate facilitate electron transfer and control the selectivity of the C-N/C-O cleavage. Notably, the method provides direct access to acyl-type radicals from unactivated amides under mild electron transfer conditions.
- Szostak, Michal,Spain, Malcolm,Eberhart, Andrew J.,Procter, David J.
-
supporting information
p. 2268 - 2271
(2014/03/21)
-
- Mechanism of SmI2/amine/H2O-promoted chemoselective reductions of carboxylic acid derivatives (esters, acids, and amides) to alcohols
-
Samarium(II) iodide-water-amine reagents have emerged as some of the most powerful reagents (E° = -2.8 V) for the reduction of unactivated carboxylic acid derivatives to primary alcohols under single electron transfer conditions, a transformation that had been considered to lie outside the scope of the classic SmI2 reductant for more than 30 years. In this article, we present a detailed mechanistic investigation of the reduction of unactivated esters, carboxylic acids, and amides using SmI2-water-amine reagents, in which we compare the reactivity of three functional groups. The mechanism has been studied using the following: (i) kinetic, (ii) reactivity, (iii) radical clock, and (iv) isotopic labeling experiments. The kinetic data indicate that for the three functional groups all reaction components (SmI2, amine, water) are involved in the rate equation and that the rate of electron transfer is facilitated by base assisted deprotonation of water. Notably, the mechanistic details presented herein indicate that complexation between SmI2, water, and amines can result in a new class of structurally diverse, thermodynamically powerful reductants for efficient electron transfer to a variety of carboxylic acid derivatives. These observations will have important implications for the design and optimization of new processes involving Sm(II)-reduction of ketyl radicals. (Chemical Equation Presented).
- Szostak, Michal,Spain, Malcolm,Eberhart, Andrew J.,Procter, David J.
-
p. 11988 - 12003
(2015/01/16)
-
- On the role of pre- and post-electron-transfer steps in the SmI 2/Amine/H2O-mediated reduction of esters: New mechanistic insights and kinetic studies
-
The mechanism of the SmI2-mediated reduction of unactivated esters has been studied using a combination of kinetic, radical clocks and reactivity experiments. The kinetic data indicate that all reaction components (SmI2, amine, H2O) are involved in the rate equation and that electron transfer is facilitated by Bronsted base assisted deprotonation of water in the transition state. The use of validated cyclopropyl-containing radical clocks demonstrates that the reaction occurs via fast, reversible first electron transfer, and that the electron transfer from simple Sm(II) complexes to aliphatic esters is rapid. Notably, the mechanistic details presented herein indicate that complexation between SmI2, H2O and amines affords a new class of structurally diverse, thermodynamically powerful reductants for efficient electron transfer to carboxylic acid derivatives as an attractive alternative to the classical hydride-mediated reductions and as a source of acyl-radical equivalents for C-C bond forming processes. Electron donors: The mechanism of the SmI 2-mediated reduction of unactivated esters has been studied by using a combination of kinetic, radical clock, and reactivity experiments. Notably, the mechanistic details presented herein indicate that complexation between SmI2, H2O, and amines gives a new class of structurally diverse, thermodynamically powerful reductants for efficient electron transfer to carboxylic acid derivatives as an attractive alternative to the classical hydride-mediated reductions and as a source of acyl-radical equivalents for C-C bond-forming processes (see scheme).
- Szostak, Michal,Spain, Malcolm,Procter, David J.
-
supporting information
p. 4222 - 4226
(2014/05/06)
-
- Copper-promoted sandmeyer trifluoromethylation reaction
-
A copper-promoted trifluoromethylation reaction of aromatic amines is described. This transformation proceeds smoothly under mild conditions and exhibits good tolerance of many synthetically relevant functional groups. It provides an alternative approach for the synthesis of trifluoromethylated arenes and heteroarenes. It also constitutes a new example of the Sandmeyer reaction.
- Dai, Jian-Jun,Fang, Chi,Xiao, Bin,Yi, Jun,Xu, Jun,Liu, Zhao-Jing,Lu, Xi,Liu, Lei,Fu, Yao
-
supporting information
p. 8436 - 8439
(2013/07/19)
-
- Enantioselective hydrosilylation of aromatic alkenes catalyzed by chiral bis(oxazolinyl)phenyl-rhodium acetate complexes
-
Highly efficient and enantioselective hydrosilylation of aromatic alkenes catalyzed by the chiral rhodium acetate complexes with the bis(oxazolinyl)phenyl ligands has been reported that afforded chiral silane derivatives with up to 99% ee. Georg Thieme Ve
- Naito, Tatsuo,Yoneda, Takuma,Ito, Jun-Ichi,Nishiyama, Hisao
-
p. 2957 - 2960
(2013/02/22)
-
- Heterocyclic compounds with carboxyl isostere groups and their use for the treatment of cardiovascular diseases
-
The present application relates to novel heterocyclic compounds, processes for their preparation, their use for the treatment and/or prophylaxis of diseases, and their use for producing medicaments for the treatment and/or prophylaxis of diseases, especia
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-
Page/Page column 49
(2009/09/25)
-
- Difluorophenol Derivatives and Their Use
-
The present application relates to novel difluorophenol derivatives, processes for their preparation, their use for the treatment and/or prophylaxis of diseases, and their use for producing medicaments for the treatment and/or prophylaxis of diseases, especially for the treatment and/or prevention of cardiovascular disorders.
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-
Page/Page column 12; 21
(2009/12/05)
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- NEW OXABISPIDINE COMPOUNDS FOR THE TREATMENT OF CARDIAC ARRHYTHMIAS
-
There is provided compounds of formula I, [Chemical formula should be inserted here. Please see paper copy] wherein R1 to R4 , R41 to R46 and Z have meanings given in the description, which are useful in the prophylaxis and in the treatment of arrhythmias, in particular atrial and ventricular arrhythmias
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Page/Page column 87
(2010/11/27)
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- Inhibitors of semicarbazide-sensitive amine oxidase (SSAO) and VAP-1 mediated adhesion useful for treatment and prevention of diseases
-
Compositions and methods of using compositions for treatment of inflammatory diseases and immune disorders are provided. Allylamino compounds are disclosed which are inhibitors of semicarbazide-sensitive amine oxidase (SSAO) and/or vascular adhesion protein 1 (VAP-1). The compounds have therapeutic utility in suppressing inflammation and inflammatory responses, and in treatment of several disorders, including multiple sclerosis and stroke.
- -
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Page/Page column 51; 59
(2008/06/13)
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- Design and synthesis of phenethyl benzo[1,4]oxazine-3-ones as potent inhibitors of PI3Kinaseγ
-
The Type 1 PI3Kinases comprise a family of enzymes, which primarily phosphorylate PIP2 to give the second messenger PIP3, a key player in many intracellular signaling processes [Science, 2002, 296, 1655; Trends Pharmacol. Sci. 2003, 24, 366]. Of the four type 1 PI3Ks, the γ-isoform, which is expressed almost exclusively in leukocytes [Curr. Biol., 1997, 7, R470], is of particular interest with respect to its role in inflammatory diseases such as rheumatoid arthritis (RA) and chronic obstructive pulmonary disease (COPD) [Mol. Med. Today, 2000, 6, 347]. Investigation of a series of 4,6-disubstituted-4H-benzo[1,4]oxazin-3-ones has led to the identification of single-digit nanomolar inhibitors of PI3Kγ, several of which had good cell based activity and were shown to be active in vivo in an aspectic peritonitis model of inflammatory cell migration.
- Lanni Jr., Thomas B.,Greene, Keri L.,Kolz, Christine N.,Para, Kimberly S.,Visnick, Melean,Mobley, James L.,Dudley, David T.,Baginski, Theodore J.,Liimatta, Marya B.
-
p. 756 - 760
(2007/10/03)
-
- Regioselective hydroboration-oxidation and -amination of fluoro-substituted styrenes
-
Hydroboration of fluorinated styrenes with common hydroborating agents results in polymerization. However, regioselective hydroboration has been achieved by utilizing iodoborane-dimethyl sulfide. A series of fluorinated β-phenethyl alcohols and amines were synthesized via this methodology.
- Ramachandran, P. Veeraraghavan,Madhi, Sateesh,O'Donnell, Martin J.
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p. 1252 - 1255
(2008/09/20)
-
- TADDOL-derived phosphites and phosphoramidites for efficient rhodium-catalyzed asymmetric hydroboration
-
Two simple TADDOL-derived monodentate ligands, the (1R,2S)-2- phenylcyclohexanol-derived phosphite and the N,N-(phenylbenzyl)-phosphoramidite, give comparably high levels of enantioselectivity (90-96% ee) in the rhodium-catalyzed hydroborations of substituted styrenes bearing either electron-donating or electron-withdrawing substituents. Rhodium(I) chloride and tetrafluoroborate catalyst precursors give comparable results. Pinacolborane is superior to catecholborane in these reactions.
- Moteki, Shin A.,Wu, Di,Chandra, Kusum L.,Sahadeva Reddy,Takacs, James M.
-
p. 3097 - 3100
(2007/10/03)
-
- 2,3-SUBSTITUTED FUSED BICYCLIC PYRIMIDIN-4(3H)-ONES WHICH MODULATE THE FUNCTION OF THE VANILLOID-1 RECEPTOR (VR1)
-
Compounds of formula (I) which are useful as therapeutic compounds, particularly in the treatment of pain and other conditions ameliorated by the modulation of the function of the vanilloid-1 receptor (VRl, also known as TRPVl).
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-
Page/Page column 19
(2008/06/13)
-
- NOVEL OXABISPIDINE COMPOUNDS AND THEIR USE IN THE TREATMENT OF CARDIAC ARRHYTHMIAS
-
There is provided compounds of formula (I), wherein R1, R2, R3, R4, R 41 to R46, A, B and G have meanings given in the description, which are useful in the prophylaxis and in the treatment of arrhythmias, in particular atrial and ventricular arrhythmias.
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Page/Page column 97
(2008/06/13)
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- DICHLOROPROPENE DERIVATIVE AND INSECTICIDE
-
PROBLEM TO BE SOLVED: To provide a dichloropropene derivative which shows an excellent activity as an active ingredient of an insecticide. SOLUTION: The dichloropropene derivative is represented by the formula (wherein X is the group:-O-A1- or the group:-N=A2- and Y is a single bond, O or S, or X and Y together represent O; Q is an optionally substituted aryl group or the like; m is 2 or 3; R1 is a halogen; n is 0 or 1; A1 is an alkylene or the like; and A2 is a alkylidyne). COPYRIGHT: (C)2006,JPOandNCIPI
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Page/Page column 38
(2010/02/14)
-
- BICYCLIC PYRIMIDIN-4-(3H)-ONES AND ANALOGUES AND DERIVATIVES THEREOF WHICH MODULATE THE FUNCTION OF THE VANILLOID-1 RECEPTOR (VR1)
-
Compounds of formula (I); which are useful as therapeutic compounds, particularly in the treatment of pain and other conditions ameliorated by the modulation of the function of the vanilloid-1 receptor (VR1).
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-
Page/Page column 48-49
(2010/02/12)
-
- Alkene-pinacolborane hydroborations catalyzed by lanthanum tris[bis(trimethylsilyl)amide]
-
Tris[bis(trimethylsilyl)amide] has been shown to be an effective catalyst for the hydroboration of representative alkenes and styrenes by pinacolborane.
- Horino, Yoshikazu,Livinghouse, Tom,Stan, Magdalena
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p. 2639 - 2641
(2007/10/03)
-
- N-substituted heterocyclic amines as modulators of chemokine receptor activity
-
The present application describes modulators of chemokine receptors of formula (I): or pharmaceutically acceptable salt forms thereof, useful for the prevention of asthma and other allergic diseases.
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Page/Page column 30
(2010/02/06)
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- ARTEMISININ-BASED PEROXIDE COMPOUNDS AS BROAD SPECTRUM ANTI-INFECTIVE AGENTS
-
Described herein is the synthesis, bioassay results and utility of new C-9 and C-10 substituted artemisinin derivatives with easily functionalizable groups attached to the artemisinin skeleton through carbon chain or heteroatoms. Described also is the demonstration of this class of compounds for their broad-spectrum anti-parasitic activity. Certain of these analogs possess noticeable cytotoxicity deliberately focused on treatment of cancerous diseases.
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Page/Page column 45-46
(2010/02/07)
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- A fast and practical approach to tetrahydropyranylation and depyranylation of alcohols using indium triflate
-
Indium triflate-mediated tetrahydropyranylation of alcohols in dichloromethane and depyranylation of these products in aqueous methanol utilizing the same reagent but different molar ratio is described. In addition, indium triflate-promoted conversion of tetrahydropyran ethers to their corresponding acetates has also been described.
- Mineno, Tomoko
-
p. 7975 - 7978
(2007/10/03)
-
- Structure-activity relationships of the antimalarial agent artemisinin. 7. Direct modification of (+)-artemisinin and in vivo antimalarial screening of new, potential preclinical antimalarial candidates
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On the basis of earlier reported quantitative structure-activity relationship studies, a series of 9β-16-(arylalkyl)-10-deoxoartemisinins were proposed for synthesis. Several of the new compounds 7 and 10-14 were synthesized employing the key synthetic intermediate 23. In a second approach, the natural product (+)-artemisinic acid was utilized as an acceptor for conjugate addition, and the resultant homologated acids were subjected to singlet oxygenation and acid treatment to provide artemisinin analogues. Under a new approach, we developed a one step reaction for the interconversion of artemisinin 1 into artemisitene 22 that did not employ selenium-based reagents and found that 2-arylethyliodides would undergo facile radical-induced conjugate addition to the exomethylene lactone of 22 in good yield. The lactone carbonyls were removed sequentially by diisobutylaluminum hydride reduction followed directly by a second reduction (BF3-etherate/Et3SiH) to afford the desired corresponding pyrans. Six additional halogen-substituted aromatic side chains were installed via 22 furnishing the bioassay candidates 15-20. The analogues were examined for in vitro antimalarial activity in the W-2 and D-6 clones of Plasmodium falciparum and were additionally tested in vivo in Plasmodium berghei- and/or Plasmodium yoelii-infected mice. Several of the compounds emerged as highly potent orally active candidates without obvious toxicity. Of these, two were chosen for pharmacokinetic evaluation, 14 and 17.
- Avery, Mitchell A.,Alvim-Gaston, Maria,Vroman, Jeffrey A.,Wu, Baogen,Ager, Arba,Peters, Wallace,Robinson, Brian L.,Charman, William
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p. 4321 - 4335
(2007/10/03)
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- The scope of catalytic asymmetric hydroboration/oxidation with rhodium complexes of 1,1'-(2-diarylphosphino-1-naphthyl)isoquinolines
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Preformed cationic Rh complexes of the title ligands are effective for the asymmetric hydroboration/oxidation of vinylarenes at ambient temperature. These vinylarenes may carry E- or Z-β substituents but not a substituents. Enantiomer excesses of up to 97% can be obtained in the most favourable cases. The enantioselectivity is moderately sensitive to the structure of the ligand: the difurylphosphino ligand gave superior results for electron-poor styrenes and the diphenylphosphino ligand the best results for electron-rich reactants. Mechanistic aspects are discussed.
- Doucet, Henri,Fernandez, Elena,Layzell, Timothy P.,Brown, John M.
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p. 1320 - 1330
(2007/10/03)
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- 2-substituted (2SR)-2-amino-2-((1SR,2SR)-2-carboxycycloprop-1- yl)glycines as potent and selective antagonists of group II metabotropic glutamate receptors. 2. Effects of aromatic substitution, pharmacological characterization, and bioavailability
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In this paper we describe the synthesis of a series of α-substituted analogues of the potent and selective group II metabotropic glutamate receptor (mGluR) agonist (1S,1'S,2'S)-carboxycyclopropylglycine (2, L-CCG 1). Incorporation of a substituent on the amino acid carbon converted the agonist 2 into an antagonist. All of the compounds were prepared and tested as a series of four isomers, i.e., two racemic diastereomers. On the basis of the improvement in affinity realized for the α-phenylethyl analogue 3, in this paper we explored the effects of substitution on the aromatic ring as a strategy to increase the affinity of these compounds for group II mGluRs. Affinity for group II mGluRs was measured using [3H]glutamic acid (Glu) binding in rat forebrain membranes. Antagonist activity was confirmed for these compounds by measuring their ability to antagonize (1S,3R)-1- aminocyclopentane-1,3-dicarboxylic acid-induced inhibition of forskolin stimulated cyclic-AMP in RGT cells transfected with human mGluR2 and mGluR3. Meta substitution on the aromatic ring of 3 with a variety of substituents, both electron donating (e.g., methyl, hydroxy, amino, methoxy, phenyl, phenoxy) and electron withdrawing (e.g., fluorine, chlorine, bromine, carboxy, trifluoromethyl) gave from 1.5- to 4.5-fold increases in affinity. Substitution with p-fluorine, as in 97 (IC50 = 0.022 ± 0.002), was the exception. Here, a greater increase in affinity was realized than for either the ortho- or meta-substituted analogues; 97 was the most potent compound resulting from monosubstitution of the aromatic. At best, only modest increases in affinity were realized for certain compounds bearing either two chlorines or two fluorines, and two methoxy groups gave no improvement in affinity (all examined in a variety of substitution patterns). Three amino acids, 4, 5, and 104, were resolved into their four constituent isomers, and affinity and functional activity for group II mGluRs was found to reside solely in the S,S,S-isomers of each, consistent with 1. With an IC50 = 2.9 ± 0.6 nM, the resolved xanthylmethyl compound 168 was the most potent compound from this SAR. Amino acid 168 demonstrated high plasma levels following intraperitoneal (ip) administration and readily penetrated into the brain. This compound, however, had only limited (~5%) oral bioavailability. Systemic administration of 168 protected mice from limbic seizures produced by the mGluR agonist 3,5-dihydroxyphenylglycine, with an ED50 = 31 mg/kg (ip, 60 min preinjection). Thus, 168 represents a valuable tool to study the role of group II mGluRs in disease.
- Ornstein, Paul L.,Bleisch, Thomas J.,Arnold, M. Brian,Kennedy, Joseph H.,Wright, Rebecca A.,Johnson, Bryan G.,Tizzano, Joseph P.,Helton, David R.,Kallman, Mary Jeanne,Schoepp, Darryle D.,Hérin, Marc
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p. 358 - 378
(2007/10/03)
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- Liquid crystalline compound and liquid crystal composition
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A liquid crystalline compound expressed by the formula STR1 wherein R1 represents an alkyl group of 1 to 12 carbon atoms, and one or two not adjacent CH2 group excluding the terminal in this group may be replaced by --CO-- group, --O
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