- Identification of (6S)-cyclopropyl-6,7-dihydropyrazolo[1,5-a]pyrazine-5(4H)-carboxamines as new HBV capsid assembly modulators
-
GYH2-18 is a type II HBV CAM with 6,7-dihydropyrazolo[1,5-a]pyrazine-5(4H)-carboxamine (DPPC) skeleton discovered by Roche INC. A series of GYH2-18 derivatives were designed, synthesized and evaluated for their anti-HBV activity. Two compounds 2f and 3k exhibited excellent anti-HBV activity, low cytotoxicity and accepted oral PK profiles. Chiral separation of 2f and 3k was conducted successfully, and (6S)-cyclopropyl DPPC isomers 2f-1, 2f-3, 3k-1 and 3k-3 were identified to be much more active than the corresponding (6R)-ones. The preliminary structure-activity relationship, particle gel assay and molecular modeling studies were also discussed, which provide useful indications for guiding the further rational design of new (6S)-cyclopropyl DPPC analogues.
- Lv, Kai,Wu, Shuo,Tao, Zeyu,Wang, Aoyu,Xu, Shijie,Yang, Lu,Gao, Qiang,Wang, Apeng,Qin, Xiaoyu,Jiang, Bin,Wu, Wenhao,Jia, Xuedong,Li, Yuhuan,Jiang, Jiandong,Liu, Mingliang
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supporting information
(2021/11/16)
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- The catalytic system ‘Rhodamine B/additive’ for the chemical fixation of CO2
-
The catalytic system ‘Rhodamine B/additive’ was introduced to promote the CO2 reactions. We synthesized various cyclic carbonates in good to excellent yields under the catalysis of rhodamine B and TBAB. A variety of 2-oxazolidinone derivatives were obtained in the presence of rhodamine B and DBU.
- Wu, Feng-tian,Wu, Ling,Cui, Chun-na
-
-
- Diethylammonium iodide as catalyst for the metal-free synthesis of 5-aryl-2-oxazolidinones from aziridines and carbon dioxide
-
The catalytic potential of ammonium halide salts was explored in the coupling reaction of a model aziridine with carbon dioxide, highlighting the superior activity of [NH2Et2]I. Then, working at room temperature, atmospheric CO2 pressure and in the absenc
- Bresciani, Giulio,Bortoluzzi, Marco,Pampaloni, Guido,Marchetti, Fabio
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p. 4152 - 4161
(2021/05/19)
-
- Pyrazolopyrazine formamide compounds containing cipropropyl segments and application thereof
-
The invention relates to a 6,7-dihydro-4H-pyrazolo[1,5-a]pyrazine-5-formamide compound represented by a formula (I), an application, a preparation method and medical application thereof, and an anti-hepatitis B pharmaceutical composition taking the 6,7-dihydro-4H-pyrazolo[1,5-a]pyrazine-5-formamide compound as an effective component. More specifically, the invention relates to a 6-cyclopropyl-N-substituted phenyl-6,7-dihydro-4H-pyrazolo[1,5-a]pyrazine-5-formamide compound, wherein in the formula (I), R, X and W are as described in the specification.
- -
-
Paragraph 0119-0124
(2020/02/27)
-
- Regioselective Ring-Opening of Styrene Oxide Derivatives Using Halohydrin Dehalogenase for Synthesis of 4-Aryloxazolidinones
-
A biocatalytic approach towards a range of 4-aryloxazolidinones is developed using a halohydrin dehalogenase from Ilumatobacter coccineus (HheG) as biocatalyst. The method is based on the HheG-catalyzed α-position regioselective ring-opening of styrene oxide derivatives with cyanate as a nucleophile, producing the corresponding 4-aryloxazolidinones in moderate to good yields. Synthesis of enantiopure 4-aryloxazolidinones is also achievable using chiral epoxide materials. (Figure presented.).
- Wan, Nanwei,Tian, Jiawei,Zhou, Xiaoying,Wang, Huihui,Cui, Baodong,Han, Wenyong,Chen, Yongzheng
-
supporting information
p. 4651 - 4655
(2019/08/27)
-
- RAD51 INHIBITORS
-
This application is directed to inhibitors of RAD51, and methods for their use, such as to treat or prevent conditions involving mitochondrial defects.
- -
-
Page/Page column 36; 117
(2019/02/02)
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- Cycloaddition of Aziridine with CO2/CS2 Catalyzed by Amidato Divalent Lanthanide Complexes
-
This is the first time that the amidato lanthanide amides ({LnLn[N(SiMe3)2]THF}2 (n = 1, Ln = Eu (1); n = 2, Ln = Eu (3), Yb (4); HL1 = tBuC6H4CONHC6H3(iPr)2; HL2 = C6H5CONHC6H3(iPr)2) and {L3Eu[N(SiMe3)2]THF}{L32Eu(THF)2} (2) (HL3 = ClC6H4CONHC6H3(iPr)2)) were applied in the cycloaddition reactions of aziridines with carbon dioxide (CO2) or carbon disulfide (CS2) under mild conditions. The corresponding oxazolidinones and thiazolidine-2-thiones were obtained in good to excellent yields with good functional group tolerance.
- Xie, Yueqin,Lu, Chengrong,Zhao, Bei,Wang, Qianyu,Yao, Yingming
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-
- Photocatalytic Oxyamination of Alkenes: Copper(II) Salts as Terminal Oxidants in Photoredox Catalysis
-
A photocatalytic method for the oxyamination of alkenes using simple nucleophilic nitrogen atom sources in place of prefunctionalized electrophilic nitrogen atom donors is reported. Copper(II) is an inexpensive, practical, and uniquely effective terminal oxidant for this process. In contrast to oxygen, peroxides, and similar oxidants commonly utilized in non-photochemical oxidative methods, the use of copper(II) as a terminal oxidant in photoredox reactions avoids the formation of reactive heteroatom-centered radical intermediates that can be incompatible with electron-rich functional groups. As a demonstration of the generality of this concept, it has been shown that diamination and deoxygenation reactions can also be accomplished using similar photooxidative conditions.
- Reed, Nicholas L.,Herman, Madeline I.,Miltchev, Vladimir P.,Yoon, Tehshik P.
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supporting information
p. 7345 - 7350
(2018/11/25)
-
- Regiospecific Bi-Catalysed Domino C-N/C-S Bonds Formation: Synthesis of 1,4-Thiazines/1,4-Thiomorpholines
-
A domino Bi-catalysed C?N/C?S bond formation of N-sulfonylaziridines is developed with 1,4-dithiane-2,5-diol to give 3,4-dihydro-1,4-thiazines at room temperature. The use of Bi(OTf)3 as a catalyst, atom economy and regioselectivity are the important practical features. (Figure presented.).
- Vijay, Murugan,Satheesh, Vanaparthi,Kumar, Sundaravel Vivek,Punniyamurthy, Tharmalingam
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p. 3030 - 3037
(2018/08/24)
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- CO2 transformation under mild conditions using tripolyphosphate-grafted KCC-1-NH2
-
Fibrous nanosilica (KCC-1) as a catalyst support was investigated in terms of stability, recycling, and reusability. For the first time, CO2 transformation was performed via the synthesis and application of KCC-1 together with sodium tripolyphosphate (STPP) and 3-aminopropyltriethoxysilane (APTES) as its functionalized derivative. To this goal, KCC-1/STPP NPs were applied to act as a nanocatalyst with excellent catalytic activities under green reaction conditions.
- Sadeghzadeh, Seyed Mohsen,Zhiani, Rahele,Moradi, Marjan
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p. 535 - 544
(2018/04/26)
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- Discovery of 3,5-Diphenyl-4-methyl-1,3-oxazolidin-2-ones as Novel, Potent, and Orally Available Δ-5 Desaturase (D5D) Inhibitors
-
The discovery and optimization of Δ-5 desaturase (D5D) inhibitors are described. Investigation of the 1,3-oxazolidin-2-one scaffold was inspired by a pharmacophore model constructed from the common features of several hit compounds, resulting in the identification of 3,5-diphenyl-1,3-oxazolidin-2-one 5h as a novel lead showing potent in vitro activity. Subsequent optimization focused on the modification of two metabolic sites, which provided (4S,5S)-5i, a derivative with improved metabolic stability. Moreover, adding a substituent into the upper phenyl moiety further enhanced the intrinsic activity, which led to the discovery of 5-[(4S,5S)-5-(4fluorophenyl)-4-methyl-2-oxo-1,3-oxazolidin-3-yl]benzene-1,3-dicarbonitrile (4S,5S)-5n, endowed with excellent D5D binding affinity, cellular activity, and high oral bioavailability in a mouse. It exhibited robust in vivo hepatic arachidonic acid/dihomo-γ-linolenic acid ratio reduction (a target engagement marker) in an atherosclerosis mouse model. Finally, an asymmetric synthetic procedure for this compound was established.
- Fujimoto, Jun,Okamoto, Rei,Noguchi, Naoyoshi,Hara, Ryoma,Masada, Shinichi,Kawamoto, Tetsuji,Nagase, Hiroki,Tamura, Yumiko Okano,Imanishi, Mitsuaki,Takagahara, Shuichi,Kubo, Kazuki,Tohyama, Kimio,Iida, Koichi,Andou, Tomohiro,Miyahisa, Ikuo,Matsui, Junji,Hayashi, Ryouta,Maekawa, Tsuyoshi,Matsunaga, Nobuyuki
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p. 8963 - 8981
(2017/11/14)
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- Two goitrogenic 1,3-oxazolidine-2-thione derivatives from Brassicales taxa: Challenging identification, occurrence and immunomodulatory effects
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1,3-Oxazolidine-2-thione derivatives are glucosinolate-related food constituents known to impart (thyreo)toxic properties to some cruciferous vegetables. In this work, 5,5-dimethyl-1,3-oxazolidine-2-thione and (-)-(R)-5-phenyl-1,3-oxazolidine-2-thione, known goitrogens, were isolated from Draba lasiocarpa Rochel (Brassicaceae) and Reseda luteola L. (Resedaceae), respectively, and were fully spectrally characterized. Subsequently, the occurrence of the two 1,3-oxazolidine-2-thiones was verified in six additional taxa out of in total 78 screened Serbian Brassicales taxa. The stereochemistry of 5-phenyl-1,3-oxazolidine-2-thione was inferred from nuclear magnetic resonance experiments with a chiral lanthanide-shift reagent, employed in this work for the first time for this type of compounds. Unexpectedly, during gas chromatography, 5-phenyl-1,3-oxazolidine-2-thione underwent an unreported thermal core isomerization (1,3-oxazolidine-2-thione to 1,3-thiazolidine-2-one). These goitrogenic volatile glucosinolate products were tested for their effect on rat macrophage viability (three assays) and nitric oxide production. It was shown that the compounds displayed different levels of cytotoxicity. All tested compounds caused a significant lactate dehydrogenase leakage, but only (R)-5-phenyl-1,3-oxazolidine-2-thione statistically significantly reduced macrophage mitochondrial activity, whereas the racemic 5-phenyl-1,3-oxazolidine-2-thione and 5,5-dimethyl-1,3-oxazolidine-2-thione had little or no effect. Again only (R)-5-phenyl-1,3-oxazolidine-2-thione exerted nitric oxide production-inhibiting properties, suggesting the higher immunomodulatory potential of this enantiomer compared with its antipode and racemic mixture.
- Radulovi?, Niko S.,Todorovska, Milica M.,Zlatkovi?, Dragan B.,Stojanovi?, Nikola M.,Randjelovi?, Pavle J.
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-
- Activation of (salen)CoI complex by phosphorane for carbon dioxide transformation at ambient temperature and pressure
-
We report the activation of (salen)CoI complex 3g by a phosphorane to form a bifunctional catalyst for the reaction of carbon dioxide with terminal epoxides or aziridines at ambient temperature and 1 bar carbon dioxide pressure. Only 1.0 mol% of both (salen)CoI 3g and phosphorane 4d are required for cyclic carbonate synthesis, and the catalyst loading could even be lowered down to 0.1 mol%. Under these conditions, no polycarbonate formation is detected by NMR analysis. It is proposed that the high efficiency originates from the activation of (salen)CoI by a phosphorane to form a phosphorane-salen Co(iii) complex with enhanced Lewis acidity for the electrophilic activation while generating an iodide anion as a Lewis base co-catalyst to facilitate the ring-opening of epoxides. Further investigation revealed that the phosphorane-(salen)CoI complex could also successfully catalyze the coupling of CO2 with aziridines under ambient conditions at a catalyst loading of 2.5 mol%.
- Zhou, Feng,Xie, Shi-Liang,Gao, Xiao-Tong,Zhang, Rong,Wang, Cui-Hong,Yin, Guang-Qiang,Zhou, Jian
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supporting information
p. 3908 - 3915
(2017/08/22)
-
- Continuous Flow Synthesis of Carbonylated Heterocycles via Pd-Catalyzed Oxidative Carbonylation Using CO and O2 at Elevated Temperatures and Pressures
-
A continuous-flow Pd-catalyzed oxidative carbonylation protocol utilizing CO and O2 gas for the synthesis of carbonylated heterocycles is described. The optimization of temperature, pressure, CO/O2 ratio, catalyst loading, and reaction time resulted in process intensified conditions for this transformation. The optimized continuous flow conditions (120 °C, 20 bar pressure, 24 min residence time) were used to prepare a number of benzoxazolone, 2-benzoxazolidinone, and other biologically and synthetically important five- and six-membered carbonylated heterocycles in good overall yield and purity (14 examples). The continuous-flow process enables the safe and scalable oxidative carbonylation using CO/O2 under elevated pressures and temperatures.
- Chen, Yuesu,Hone, Christopher A.,Gutmann, Bernhard,Kappe, C. Oliver
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p. 1080 - 1087
(2017/07/26)
-
- Converting urea into high value-added 2-oxazolidinones under solvent-free conditions
-
Zn-modified mesoporous Mg-Al nanoplates oxides were prepared by co-precipitation and further characterized and used in the synthesis of 2-oxazolidinones from urea and epoxides under solvent-free conditions. The characterization results suggested that Zn1.1Mg2.0AlO4.6, which featured more accessible active medium basic sites, were favorable for obtaining superior catalytic activity. This synthetic process is mild, convenient, simple and gives good yields up to 80%.
- Wang, Peixue,Li, Qinghe,Liu, Shimin,Deng, Youquan
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p. 94382 - 94386
(2016/10/21)
-
- Practical Synthetic Procedures for the Iron-Catalyzed Intermolecular Olefin Aminohydroxylation Using Functionalized Hydroxylamines
-
A set of practical synthetic procedures for the iron-catalyzed intermolecular olefin aminohydroxylation reactions in gram scale is reported. In these transformations, a bench-stable functionalized hydroxylamine is applied as the amination reagent. This method is compatible with a broad range of synthetically valuable olefins including those that are incompatible with the existing aminohydroxylation methods. It also provides valuable amino alcohol building blocks with regio- and stereochemical arrays that are complementary to known methods.
- Zhu, Cheng-Liang,Lu, Deng-Fu,Sears, Jeffrey D.,Jia, Zhen-Xin,Xu, Hao
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p. 3031 - 3041
(2016/09/09)
-
- Development and validation of a docking-based virtual screening platform for the identification of new lactate dehydrogenase inhibitors
-
The human muscle isoform of lactate dehydrogenase (hLDH5) is one of the key enzymes of the glycolytic process. It is overexpressed in metastatic cancer cells and is linked to the vitality of tumors in hypoxic conditions. With the aim of identifying new hLDH5 inhibitors, a fully automated docking-based virtual screening platform was developed by considering different protein conformations and the consensus docking strategy. In order to verify the reliability of the reported platform, a small database of about 10,000 compounds was filtered by using this method, and the top-ranked compounds were tested for their hLDH5 inhibition activity. Enzymatic assays revealed that, among the ten selected compounds, two proved to efficiently inhibit enzyme activity with IC50 values in the micromolar range. These results demonstrate the validity of the methodologies we followed, encouraging the application of larger virtual screening studies and further refinements of the platform. Furthermore, the two active compounds herein described may be considered as interesting leads for the development of new and more efficient LDH inhibitors.
- Granchi, Carlotta,Capecchi, Alice,Del Frate, Gianluca,Martinelli, Adriano,Macchia, Marco,Minutolo, Filippo,Tuccinardi, Tiziano
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p. 8772 - 8790
(2015/09/01)
-
- Aluminium-Catalysed Oxazolidinone Synthesis and their Conversion into Functional Non-Symmetrical Ureas
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An efficient and practical aluminium-catalysed approach towards a range of functional oxazolidinones is reported. The method is based on cheap and readily available starting materials including terminal and internal (bicyclic) epoxides and phenyl carbamate. The oxazolidinones serve as highly useful synthons for the high yield preparation of non-symmetrical ureas by nucleophilic ring-opening affording the targeted urea compounds with excellent functional group diversity, high regioselectivity and isolated yields up to >99%.
- Laserna, Victor,Guo, Wusheng,Kleij, Arjan W.
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p. 2849 - 2854
(2015/09/28)
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- Efficient synthesis of 2-oxazolidinones from epoxides and carbamates catalyzed by amine-functionalized ionic liquids
-
A series of amine-functionalized ionic liquids were prepared and their catalytic performance was tested in the synthesis of 2-oxazolidinones from epoxides and carbamates. Under optimized reaction conditions, good to excellent yields of various 2-oxazolidinones were achieved with different epoxides and carbamates. Moreover, the amine-functionalized ionic liquid catalyst could be easily recovered and reused without significant loss in activity.
- Shang, Jianpeng,Li, Zuopeng,Su, Caina,Guo, Yong,Deng, Youquan
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p. 71765 - 71769
(2015/09/08)
-
- Iron(II)-catalyzed intermolecular amino-oxygenation of olefins through the N - O bond cleavage of functionalized hydroxylamines
-
An iron-catalyzed diastereoselective intermolecular olefin amino-oxygenation reaction is reported, which proceeds via an iron-nitrenoid generated by the N - O bond cleavage of a functionalized hydroxylamine. In this reaction, a bench-stable hydroxylamine derivative is used as the amination reagent and oxidant. This method tolerates a range of synthetically valuable substrates that have been all incompatible with existing amino-oxygenation methods. It can also provide amino alcohol derivatives with regio- and stereochemical arrays complementary to known amino-oxygenation methods.
- Lu, Deng-Fu,Zhu, Cheng-Liang,Jia, Zhen-Xin,Xu, Hao
-
supporting information
p. 13186 - 13189
(2015/03/30)
-
- Amine functionalized MCM-41 as a green, efficient, and heterogeneous catalyst for the regioselective synthesis of 5-aryl-2-oxazolidinones, from CO2 and aziridines
-
Covalently linked amine functionalized MCM-41 catalysts were investigated as an efficient, heterogeneous and recyclable catalyst for the coupling of carbon dioxide (CO2) and aziridines providing high conversion with excellent regioselectivity towards 5-aryl-2-oxazolidinones under mild and solvent free conditions. The effect of various reaction parameters, such as temperature, time, and CO2 pressure for the synthesis of 5-aryl-2-oxazolidinones using amine functionalized MCM-41 catalyst was investigated. The optimized protocol was applied to a wide variety of 1-alkyl-2-arylaziridines producing the corresponding 5-aryl-2-oxazolidinones with good yield and excellent regioselectivity. Amine functionalized MCM-41 catalysts were characterized by FT-IR, TG/DTA, high and low angle XRD, and solid state 29Si CPMAS NMR analysis. Furthermore, the catalyst was effectively recycled for five consecutive cycles without any significant loss in its catalytic activity and selectivity under the described reaction conditions. Readily available reagents, mild reaction conditions and effective catalyst recyclability make this protocol simple, convenient, practical and environmentally friendly.
- Nale, Deepak B.,Rana, Surjyakanta,Parida, Kulamani,Bhanage, Bhalchandra M.
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p. 340 - 349
(2013/11/19)
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- Catalytic fluoride triggers dehydrative oxazolidinone synthesis from CO2
-
Herein, catalytic fluoride (F-) is demonstrated to be a trigger for dehydrative immobilization of atmospheric pressure CO2, such that reaction of CO2 with β-amino alcohols derived from natural amino acids gives optically pure oxazolidinones in high yields. A synergistic combination of fluoride and organosilicon agents (e.g., Bu4NF + Ph3SiF or siloxanes) enhances the catalytic activity and functional group compatibility. This system lies at the interface between homogenous and heterogeneous catalysis, and may prove useful for the development of recoverable/reusable siloxane-based CO2 immobilization materials. This journal is
- Takada, Yuki,Foo, Siong Wan,Yamazaki, Yusuke,Saito, Susumu
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p. 50851 - 50857
(2015/02/19)
-
- 5-HT RECEPTOR MODULATORS
-
The invention relates to compounds of formula (I), useful for treating disorders mediated by the 5-hydroxytryptamine (serotonin) receptor IB (5-HT1B), e.g. vascular disorders, cancer and CNS disorders. The invention also provides methods of treating such disorders, and compounds and compositions etc. for their treatment.
- -
-
Paragraph 0611; 0612
(2013/03/26)
-
- Ethyl imidazole-1-carboxylate (EImC) as a carbonylating agent: Efficient synthesis of oxazolidin-2-ones from amino alcohols
-
Various substituted oxazolidin-2-ones were synthesized from the corresponding amino alcohols using ethyl imidazole- 1-carboxylate (EImC). Highly substituted and sterically hindered amino alcohols and amino alcohols having a free hydroxy group were cyclized to oxazolidin-2-ones efficiently. This method is simple and produces oxazolidin-2-ones in very good yield.
- Veeraswamy,Reddy, K. Indrasena,Ragavan, R. Venkat,Yennam, Satyanarayana,Jayashree
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p. 109 - 111
(2013/03/14)
-
- Efficient synthesis of 2-oxazolidinone from epoxides and carbamates with binary MgFe oxides as a magnetic solid base catalyst
-
Magnetic binary MgFe oxides were prepared by co-precipitation method, characterized and tested in the synthesis of 2-oxazolidinones from epoxides and carbamates. The catalytic results showed that the catalyst with Mg/Fe molar ratio of 1 and calcined at 400°C exhibited superior catalytic activity. The catalyst could be magnetically separated, recycled and reused for five runs without noticeable deactivation. Under the optimized conditions, various 2-oxazolidinones derivatives were successfully synthesized with good to excellent isolated yields.
- Shang, Jianpeng,Liu, Shimin,Lu, Liujin,Ma, Xiangyuan,He, Yude,Deng, Youquan
-
-
- Synthesis of some 2-Oxazolidinones in mild conditions
-
One step efficient protocol for the synthesis of 2-oxazolidinones in paste chemical medium is described under microwave activation with 80 % yield.
- Bratulescu, George
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experimental part
p. 929 - 930
(2011/12/15)
-
- 5-HT RECEPTOR MODULATORS
-
The invention relates to compounds of formula (I), useful for treating disorders mediated by the 5-hydroxytryptamine (serotonin) receptor 1B (5-HT1B), e.g. vascular disorders, cancer and CNS disorders. The invention also provides methods of treating such disorders, and componnds and compositions etc. for their treatment
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-
Page/Page column 62-63
(2011/09/15)
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- GSK-3BETA INHIBITOR
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For the purpose of providing a GSK-3β inhibitor containing a 2-aminopyridine compound or a salt thereof or a prodrug thereof useful as an agent for the prophylaxis or treatment of a GSK-3β-related pathology or disease, the present invention provides a GSK-3β inhibitor containing a compound represented by the formula (IA): wherein each symbol is as defined in the specification. or a salt thereof or a prodrug thereof.
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-
Page/Page column 26
(2011/04/13)
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- Regioselective synthesis of 5-aryl-2-oxazolidinones from carbon dioxide and aziridines using Br- Ph3+PPEG 600P+Ph3Br- as an efficient, homogenous recyclable catalyst at ambient conditions
-
Polyethylene glycol functionalized phosphonium salt (Br- Ph 3+PPEG600P+Ph3Br -) was found to be an efficient, homogenous, recyclable catalyst for coupling of CO2 with a variety of aziridines producing corresponding 5-aryl-2-oxazolidinones with good yields and excellent regioselectivity under relatively mild and solvent free conditions. Furthermore, the catalyst was effectively recycled for four consecutive cycles without any significant loss in its catalytic activity and selectivity.
- Watile, Rahul A.,Bagal, Dattatraya B.,Patil, Yogesh P.,Bhanage, Bhalchandra M.
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p. 6383 - 6387
(2011/12/22)
-
- Polymer supported diol functionalized ionic liquids: An efficient, heterogeneous and recyclable catalyst for 5-aryl-2-oxazolidinones synthesis from CO2 and aziridines under mild and solvent free condition
-
Polymer supported diol functionalized ionic liquids (PS-DFILXs) were investigated as an efficient, heterogeneous and recyclable catalyst for coupling of carbon dioxide (CO2) to aziridines providing high conversion with excellent regioselectivit
- Watile, Rahul A.,Bagal, Dattatraya B.,Deshmukh, Krishna M.,Dhake, Kishor P.,Bhanage, Bhalchandra M.
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experimental part
p. 196 - 203
(2012/02/03)
-
- Lewis basic ionic liquids-catalyzed synthesis of 5-aryl-2-oxazolidinones from aziridines and CO2 under solvent-free conditions
-
A series of easily prepared Lewis basic ionic liquids were developed as recyclable and efficient catalysts for selective synthesis of 5-aryl-2-oxazolidinones from aziridines and CO2 without utilization of any organic solvent or additive. Notably, high conversion, chemo- and regio-selectivity were attained when 1-butyl-4-aza-1-azaniabicyclo[2.2.2]octane bromide ([C4DABCO]Br) was used as the catalyst. Furthermore, the catalyst could be recycled over four times without appreciable loss of catalytic activity. The effects of the catalyst structure and various reaction parameters on the catalytic performance were investigated in detail. This protocol was found to be applicable to a variety of aziridines producing the corresponding 5-aryl-2-oxazolidinones in good yields and excellent regioselectivities. Therefore, this solvent-free process thus represents an environmentally friendly process for ionic liquid-catalyzed conversion of CO2 into value-added chemicals. A possible catalytic cycle for CO2 activation induced by nucleophilic tertiary nitrogen of the ionic liquid was proposed, based on studies using in situ FT-IR spectroscopy under CO2 pressure.
- Yang, Zhen-Zhen,He, Liang-Nian,Peng, Shi-Yong,Liu, An-Hua
-
supporting information; experimental part
p. 1850 - 1854
(2011/02/23)
-
- Naturally occurring α-amino acid: a simple and inexpensive catalyst for the selective synthesis of 5-aryl-2-oxazolidinones from CO2 and aziridines under solvent-free conditions
-
Naturally occurring α-amino acid successfully catalyzed cycloaddition of aziridine with carbon dioxide to afford 5-aryl-2-oxazolisinones under mild conditions without the need of any additives. The scope of this reaction is very general, providing the corresponding products in good yields and excellent regioselectivity (87:13-100:0) regardless of the α-amino acid examined and a wide variety of N-substituted aziridines employed. Two possible reaction pathways for the reaction were also discussed.
- Jiang, Huan-Feng,Ye, Jin-Wu,Qi, Chao-Rong,Huang, Liang-Bin
-
experimental part
p. 928 - 932
(2010/05/18)
-
- Catalyst-free process for the synthesis of 5-aryl-2-oxazolidinones via cycloaddition reaction of aziridines and carbon dioxide
-
A simple approach for facile synthesis of 5-aryl-2-oxazolidinones in excellent regioselectivity from aziridines under compressed CO2 conditions was developed in the absence of any catalyst and organic solvent. The reaction outcome was found to be tuned by subtly adjusting CO2 pressure. The adduct formed in situ of aziridine and CO2 is assumed to act as a catalyst in this reaction, which was also studied by means of in situ FT-IR technique.
- Dou, Xiao-Yong,He, Liang-Nian,Yang, Zhen-Zhen,Wang, Jing-Lun
-
supporting information; experimental part
p. 2159 - 2163
(2010/10/21)
-
- Environmentally benign chemical fixation of CO2 catalyzed by the functionalized ion-exchange resins
-
Basic ion-exchange resins, one kind of polystyryl-supported tertiary amine, were demonstrated to be highly efficient and recyclable catalysts for the fixation of carbon dioxide with aziridines under mild conditions, leading to the formation of 5-aryl-2-oxazolidinone with excellent regio-selectivities. Notably, neither solvents nor any additives were required, and the catalyst could be recovered by simple filtration and directly reused at least five times without significant loss of catalytic activity and selectivity. The present protocol has been applied to reactions of epoxides/propargyl amines with CO 2/CS2. This solvent-free process thus represents environmentally friendly catalytic conversion of CO2 into value-added chemicals and may have potential in various continuous flow reactors in industry.
- Liu, Anhua,He, Liangnian,Peng, Shiyong,Pan, Zhongda,Wang, Jinglun,Gao, Jian
-
experimental part
p. 1578 - 1585
(2010/11/04)
-
- Polystyrene-supported amino acids as efficient catalyst for chemical fixation of carbon dioxide
-
Four new polystyrene-supported amino acids have been synthesized and applied to the chemical fixation of carbon dioxide for the first time. Two series of experiments with polystyrene-supported threonine (PS-Thr) and polystyrene-supported tyrosine (PS-Tyr) as catalyst, respectively, were conducted to study the effect of the reaction conditions on the carboxylation of propylene oxide/carbon dioxide. There was no considerable decrease in the yield of propylene carbonate after the polystyrene-supported amino acids were used five times, indicating that these catalysts are very stable. It was demonstrated that these catalysts were very efficient in the carboxylation of various epoxides and aziridines with carbon dioxide under mild conditions without any solvents. The mechanism for this carboxylation is also discussed.
- Qi, Chaorong,Ye, Jinwu,Zeng, Wei,Jiang, Huanfeng
-
supporting information; experimental part
p. 1925 - 1933
(2010/11/04)
-
- Zirconyl chloride: an efficient recyclable catalyst for synthesis of 5-aryl-2-oxazolidinones from aziridines and CO2 under solvent-free conditions
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Zirconyl chloride was found to be an efficient catalyst for the cycloaddition reaction of aziridines with CO2, thus leading to the preferential formation of 5-aryl-2-oxazolidinones under solvent-free conditions. The methodology could be extended to various substituted aziridines with high conversion and chemo-, regio-, and stereoselectivity. Furthermore, the catalyst could be reused over five times without significant loss in activity. Interestingly, the recovered catalyst showed higher activity in comparison with the fresh catalyst, presumably due to its morphological variation. The use of this cheap and moisture stable catalyst make this protocol practical, environmentally benign, and economically attractive.
- Wu, Ying,He, Liang-Nian,Du, Ya,Wang, Jin-Quan,Miao, Cheng-Xia,Li, Wei
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experimental part
p. 6204 - 6210
(2011/03/21)
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- Quaternary ammonium bromide functionalized polyethylene glycol: A highly efficient and recyclable catalyst for selective synthesis of 5-aryl-2-oxazolidinones from carbon dioxide and aziridines under solvent-free conditions
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(Chemical Equation Presented) A quaternary ammonium bromide covalently bound to polyethylene glycol (PEG, MW = 6000), i.e., PEG6000- (NBu3Br)2, was found to be an efficient and recyclable catalyst for the cycloaddition reaction of aziridines to CO2 under mild conditions without utilization of additional organic solvents or cocatalysts. As a result, 5-aryl-2-oxazolidinone was obtained in high yield with excellent regioselectivity. The catalyst worked well for a wide variety of 1-alkyl-2-arylaziridines. Besides, the catalyst could be recovered by centrifugation and reused without significant loss of catalytic activity and selectivity.
- Du, Ya,Wu, Ying,Liu, An-Hua,He, Liang-Nian
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p. 4709 - 4712
(2008/09/21)
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- A facile one-pot solid-phase synthesis of oxazolidin-2-ones using polymer-supported 2-hydroxyalkyl selenide reagent
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A simple, efficient and environmentally friendly procedure for one-pot solid-phase synthesis of 2-oxazolidinones in moderate to good yields by reaction of polystyrene-supported 2-hydroxyalkyl selenide with benzoyl isocyanate and subsequent oxidation/cycli
- Hu, Qiao-Sheng,Sheng, Shou-Ri,Lin, Shu-Ying,Wei, Mei-Hong,Xin, Qin,Liu, Xiao-Ling
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- Facile one-pot synthesis of oxazolidin-2-ones from phenyl 2-hydroxyalkyl selenides
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A novel, convenient, efficient, three-step, one-pot synthesis of 2-oxazolidinones from phenyl 2-hydroxyalkyl selenides was developed. Using this methodology, 2-oxazolidinones are obtained in good yields (76-85%) by reaction of phenyl 2-hydroxyalkyl seleni
- Sheng, Shou-Ri,Luo, Hai-Rong,Huang, Zhen-Zhong,Sun, Wu-Kang,Liu, Xiao-Ling
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p. 2693 - 2699
(2008/02/12)
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- Pd(OAc)2-catalyzed carbonylation of amines
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A phosphine-free catalytic system [Pd(OAc)2-Cu(OAc) 2-air] induced a substrate-specific carbonylation of amines in boiling toluene under CO gas (1 atm). Symmetrical N,N′-dialkylureas were obtained by the carbonylation of primary amines. N,N,N′-Trialkylureas were selectively formed by addition of a secondary amine to the above reaction vessel. Secondary amines did not give tetraalkylureas. However, dialkylamines with a phenyl group on their alkyl chains, such as N-monoalkylated benzylic amine or phenethylamine derivatives, underwent a direct aromatic carbonylation to afford five- or six-membered benzolactams. In the carbonylation, the chelation effect or steric repulsion between Pd(II) and the meta-substituent in the ortho-palladation and the ring sizes of cyclopalladation products that were formed prior to carbonylation were found to generate good site selectivity and increase the reaction rate. In contrast, carbonylation of ω- arylalkylamines with a hydroxyl group gave neither ureas nor benzolactams but instead produced 1,3-oxazolidinones smoothly. Hydrochlorides of amines also underwent carbonylation to afford the corresponding amides under the conditions used. This procedure made it possible to prepare ureas of amino acid esters and N-alkylcarbamates in practical yields.
- Orito, Kazuhiko,Miyazawa, Mamoru,Nakamura, Takatoshi,Horibata, Akiyoshi,Ushito, Harumi,Nagasaki, Hideo,Yuguchi, Motoki,Yamashita, Satoshi,Yamazaki, Tetsuro,Tokuda, Masao
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p. 5951 - 5958
(2007/10/03)
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- MONOCYCLIC ANILIDE SPIROHYDANTOIN CGRP RECEPTOR ANTAGONISTS
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The present invention is directed to compounds that are antagonists of CGRP receptors and that are useful in the treatment or prevention of diseases in which the CGRP is involved, such as headache, migraine and cluster headache. The invention is also directed to pharmaceutical compositions comprising these compounds and the use of these compounds and compositions in the prevention or treatment of such diseases in which CGRP is involved.
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- Chemical fixation of carbon dioxide co-catalyzed by a combination of Schiff bases or phenols and organic bases
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Binaphthyldiamino, ethyldiamino and cyclohexyldiamino Schiff bases can catalyze the reaction of epoxides with carbon dioxide in the presence of catalytic amounts of various organic bases to give the corresponding cyclic carbonates in high yields. The simplest binaphthyldiamino Schiff base, derived from the reaction of binaphthyldiamine with salicylaldehyde, gave the highest yield of cyclic carbonate. This catalytic system can be further simplified by use of a phenol instead of the Schiff base to give the corresponding cyclic carbonates in high yields as well. Mechanistic insights were obtained based on a deuterium labeling experiment, The reaction of aziridines with CO2 and epoxide with CS2 were also examined under the same reaction conditions. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Shen, Yu-Mei,Duan, Wei-Liang,Shi, Min
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p. 3080 - 3089
(2007/10/03)
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- Regioselective aminobromination of terminal alkenes
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The addition of t-butyl N,N-dibromocarbamate (BBC) to a variety of terminal alkenes has been studied. The reaction was spontaneously initiated and proceeded smoothly in refluxing dichloromethane. The N-bromo adducts, formed upon addition, could be reduced
- ?liwińska, Anna,Zwierzak, Andrzej
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p. 5927 - 5934
(2007/10/03)
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- An improved procedure for the palladium-catalyzed oxidative carbonylation of β-amino alcohols to oxazolidin-2-ones
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A highly efficient oxidative cyclocarbonylation of β-amino alcohols and 2-aminophenol to oxazolidin-2-ones has been achieved by using PdI2 in conjunction with KI as the catalytic system in DME under relatively mild conditions (100 °C and 20 atm of a 4:1 mixture of CO and air).
- Gabriele, Bartolo,Mancuso, Raffaella,Salerno, Giuseppe,Costa, Mirco
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p. 601 - 604
(2007/10/03)
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- Regioselectivity and selective enhancement of carbon dioxide fixation of 2-substituted aziridines to 2-oxazolidinones under supercritical conditions
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Under supercritical CO2 conditions, regioselectivity in the carbon dioxide fixation of 2-substituted aziridines to 2-oxazolidinones was observed with good yields around 75%. Furthermore, when propylene imine was used in the place of aziridine,
- Kawanami, Hajime,Ikushima, Yutaka
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p. 3841 - 3844
(2007/10/03)
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- Synthesis of 2-oxazolidones by sulfur-assisted thiocarboxylation with carbon monoxide and oxidative cyclization with molecular oxygen under mild conditions
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Simple synthetic method on 2-oxazolidone derivatives was established. 2-Aminoethanols were easily subjected to the thiocarboxylation with carbon monoxide promoted by elemental sulfur, followed by the oxidative cyclization with molecular oxygen to give corresponding 2-oxazolidones in good yields under mild conditions (1 atm, rt). Furthermore, 2-imidazolidones and 2-thiazolidone were also prepared in good yields similarly.
- Mizuno, Takumi,Takahashi, Junko,Ogawa, Akiya
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p. 7805 - 7808
(2007/10/03)
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- An efficient conversion of allyl esters to urethanes with Pd catalyst
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Reaction of allyl esters in a proper alcohol with Pd catalyst in the presence of (PhO)2P(O)N3 and NaN3 at 80 °C directly gave urethanes. The reactions in t-BuOH afforded amines protected with Boc.
- Okumoto, Hiroshi,Nishihara, Satoshi,Yamamoto, Sinya,Hino, Hirokazu,Nozawa, Akihiro,Suzuki, Akira
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p. 991 - 992
(2007/10/03)
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- Synthesis of 2-oxazolidinones by direct palladium-catalyzed oxidative carbonylation of 2-amino-1-alkanols
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(equation presented) 2-Oxazolidinones 2 are obtained in excellent yields (up to 100%) and with unprecedented catalytic efficiencies (up to 2000 mol of product/mol of catalyst used) by direct Pdl2/Kl-catalyzed oxidative carbonylation of the readily available 2-amino-1-alkanols 1. Reactions are carried out in MeOH as the solvent at 100 °C using a 1/6/5 CO/O2/air mixture (60 atm total pressure at 25 °C).
- Gabriele, Bartolo,Salerno, Giuseppe,Brindisi, Donatella,Costa, Mirco,Paolo Chiusoli, Gian
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p. 625 - 626
(2007/10/03)
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- Electrophilic peptide analogs as inhibitors of trypsin-like enzymes
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This invention relates to electrophilic dipeptide analogs conjugated to an N,N-disubstituted alpha -amino acid as inhibitors of trypsin-like serine protease enzymes.
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- Electrosynthesis of cyclic carbamates from aziridines and carbon dioxide
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A new and selective synthesis of five-membered ring cyclic carbamates involving nickel-catalyzed CO2 incorporation into aziridines under mild electrochemical conditions was carried out in good yields.
- Tascedda, Patricia,Dunach, Elisabet
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p. 449 - 450
(2007/10/03)
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