- A fast and efficient bromination of isoxazoles and pyrazoles by microwave irradiation
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A fast and efficient method has been developed for the bromination of isoxazoles and pyrazoles using microwave irradiation. In this method, N-bromosuccinimide was used in different acid solvents according to the reactivity of the substrates to give mono-b
- Li, Guo,Kakarla, Ramesh,Gerritz, Samuel W.
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- Toward the Validation of Maternal Embryonic Leucine Zipper Kinase: Discovery, Optimization of Highly Potent and Selective Inhibitors, and Preliminary Biology Insight
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MELK kinase has been implicated in playing an important role in tumorigenesis. Our previous studies suggested that MELK is involved in the regulation of cell cycle and its genetic depletion leads to growth inhibition in a subset of high MELK-expressing ba
- Barry Touré,Giraldes, John,Smith, Troy,Sprague, Elizabeth R.,Wang, Yaping,Mathieu, Simon,Chen, Zhuoliang,Mishina, Yuji,Feng, Yun,Yan-Neale, Yan,Shakya, Subarna,Chen, Dongshu,Meyer, Matthew,Puleo, David,Tres Brazell,Straub, Christopher,Sage, David,Wright, Kirk,Yuan, Yanqiu,Chen, Xin,Duca, Jose,Kim, Sean,Tian, Li,Martin, Eric,Hurov, Kristen,Shao, Wenlin
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- Unveiling Potent Photooxidation Behavior of Catalytic Photoreductants
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We describe a photocatalytic system that reveals latent photooxidant behavior from one of the most reducing conventional photoredox catalysts, N-phenylphenothiazine (PTH). This aerobic photochemical reaction engages difficult to oxidize feedstocks, such as benzene, in C(sp2)-N coupling reactions through direct oxidation. Mechanistic studies are consistent with activation of PTH via photooxidation and with Lewis acid cocatalysts scavenging inhibitors inextricably formed in this process.
- Targos, Karina,Williams, Oliver P.,Wickens, Zachary K.
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supporting information
p. 4125 - 4132
(2021/04/07)
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- Teaching Old Compounds New Tricks: DDQ-Photocatalyzed C?H Amination of Arenes with Carbamates, Urea, and N-Heterocycles
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The C?H amination of benzene derivatives was achieved using DDQ as photocatalyst and BocNH2 as the amine source under aerobic conditions and visible light irradiation. Electron-deficient and electron-rich benzenes react as substrates with moderate to good product yields. The amine scope of the reaction comprises Boc-amine, carbamates, pyrazoles, sulfonimides and urea. Preliminary mechanistic investigations indicate arene oxidation by the triplet of DDQ to radical cations with different electrophilicity and a charge transfer complex between the amine and DDQ as intermediate of the reaction.
- Das, Somnath,Natarajan, Palani,K?nig, Burkhard
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supporting information
p. 18161 - 18165
(2017/12/28)
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- A quick, mild and efficient bromination using a CFBSA/KBr system
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Bromination is a fundamental transformation in organic chemistry and brominated compounds as building blocks are of paramount importance in organic synthesis. In our study, we have developed an efficient method of bromination by using a CFBSA/KBr system at room temperature in a short reaction time. Notably, this approach has been proven to be applicable to a range of substrates including 1,3-diketones and β-keto esters, phenols, aromatic amines and heteroarenes with good to excellent yields.
- Jiang, Pan-Pan,Yang, Xian-Jin
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p. 90031 - 90034
(2016/10/09)
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- Framework-Copper-Catalyzed C?N Cross-Coupling of Arylboronic Acids with Imidazole: Convenient and Ligand-Free Synthesis of N-Arylimidazoles
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A convenient and environmentally benign synthesis of N-arylimidazoles has been demonstrated by a straightforward reaction catalyzed by the unsaturated coordination sites of Cu in the copper terephthalate metal–organic framework (Cu(tpa)-MOF). A series of N-arylimidazoles has been synthesized in excellent yields by the C?N cross-coupling reaction of arylboronic acids and imidazoles catalyzed by the Cu(tpa)-MOF using ethanol as a benign solvent. The present ligand-free catalytic system proceeds smoothly under mild conditions, avoids stoichiometric Cu reagents, tolerates many functional groups, has a wide substrate scope, and is feasible with other nitrogen heterocycles. The stability and heterogeneity of the catalyst is evidenced by the results of a heterogeneity test, and the catalyst can be reused several times without a loss of activity. The easy preparation of the catalyst, its stability, recovery by simple filtration, and reusability reveal Cu(tpa) MOF as a versatile catalyst for academic and industrial applications.
- Devarajan, Nainamalai,Suresh, Palaniswamy
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p. 2953 - 2960
(2016/09/28)
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- Selective Halogenation Using an Aniline Catalyst
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Electrophilic halogenation is used to produce a wide variety of halogenated compounds. Previously reported methods have been developed mainly using a reagent-based approach. Unfortunately, a suitable "catalytic" process for halogen transfer reactions has yet to be achieved. In this study, arylamines have been found to generate an N-halo arylamine intermediate, which acts as a highly reactive but selective catalytic electrophilic halogen source. A wide variety of heteroaromatic and aromatic compounds are halogenated using commercially available N-halosuccinimides, for example, NCS, NBS, and NIS, with good to excellent yields and with very high selectivity. In the case of unactivated double bonds, allylic chlorides are obtained under chlorination conditions, whereas bromocyclization occurs for polyolefin. The reactivity of the catalyst can be tuned by varying the electronic properties of the arene moiety of catalyst.
- Samanta, Ramesh C.,Yamamoto, Hisashi
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supporting information
p. 11976 - 11979
(2015/08/18)
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- Efficient and Practical Oxidative Bromination and Iodination of Arenes and Heteroarenes with DMSO and Hydrogen Halide: A Mild Protocol for Late-Stage Functionalization
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An efficient and practical system for inexpensive bromination and iodination of arenes as well as heteroarenes by using readily available dimethyl sulfoxide (DMSO) and HX (X = Br, I) reagents is reported. This mild oxidative system demonstrates a versatile protocol for the synthesis of aryl halides. HX (X = Br, I) are employed as halogenating reagents when combined with DMSO which participates in the present chemistry as a mild and inexpensive oxidant. This oxidative system is amenable to late-stage bromination of natural products. The kilogram-scale experiment (>95% yield) shows great potential for industrial application.
- Song, Song,Sun, Xiang,Li, Xinwei,Yuan, Yizhi,Jiao, Ning
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supporting information
p. 2886 - 2889
(2015/06/30)
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- Substituted diazabicycloakane derivatives
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Compounds of formula (I) Z-Ar1—Ar2??(I) wherein Z is a diazabicyclic amine, Ar1 is a 5- or 6-membered aromatic ring, and Ar2 is selected from an unsubstituted or substituted 5-membered heteroaryl ring; an unsubstituted or substituted 6-membered heteroaryl ring; 3,4-(methylenedioxy)phenyl; and phenyl substituted with 0, 1, 2, or 3 substituents in the meta- or para-positions. The compounds are useful in treating conditions or disorders prevented by or ameliorated by α7 nAChR ligands. Also disclosed are pharmaceutical compositions comprising compounds of formula (I) and methods for using such compounds and compositions.
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Page/Page column 31
(2010/02/11)
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- Substituted diazabicycloalkane derivatives
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Compounds of formula (I) [in-line-formulae]Z-Ar1—Ar2??(I) [/in-line-formulae] wherein Z is a diazabicyclic amine, Ar1 is a 5- or 6-membered aromatic ring, and Ar2 is selected from the group consisting of an unsubstituted or substituted 5- or 6-membered heteroaryl ring; unsubstituted or substituted bicyclic heteroaryl ring; 3,4-(methylenedioxy)phenyl; carbazolyl; tetrahydrocarbazolyl; naphthyl; and phenyl; wherein the phenyl is substituted with 0, 1, 2, or 3 substituents in the meta- or para-positions. The compounds are useful in treating conditions or disorders prevented by or ameliorated by α7 nAChR ligands. Also disclosed are pharmaceutical compositions comprising compounds of formula (I) and methods for using such compounds and compositions.
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Page/Page column 68
(2010/02/11)
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