- Enantioselective Synthesis of Pyroglutamic Acid Esters from Glycinate via Carbonyl Catalysis
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Direct α-functionalization of NH2-free glycinates with relatively weak electrophiles such as α,β-unsaturated esters still remains a big challenge in organic synthesis. With chiral pyridoxal 5 d as a carbonyl catalyst, direct asymmetric conjugated addition at the α-C of glycinate 1 a with α,β-unsaturated esters 2 has been successfully realized, to produce various chiral pyroglutamic acid esters 4 in 14–96 % yields with 81–97 % ee's after in situ lactamization. The trans and cis diastereomers can be obtained at the same time by chromatography and both of them can be easily converted into chiral 4-substituted pyrrolidin-2-ones such as Alzheimer's drug Rolipram (11) with the same absolute configuration via tert-butyl group removal and subsequent Barton decarboxylation.
- Ma, Jiguo,Zhou, Qinghai,Song, Guanshui,Song, Yongchang,Zhao, Guoqing,Ding, Kuiling,Zhao, Baoguo
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supporting information
p. 10588 - 10592
(2021/04/06)
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- Mizoroki-Heck Reaction of Unstrained Aryl Ketones via Ligand-Promoted C-C Bond Olefination
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Mizoroki-Heck reaction of unstrained aryl ketone with acrylate/styrene is accomplished via palladium-catalyzed ligand-promoted C-C bond cleavage. Various (hetero)aryl ketones are compatible in the reaction, affording the alkene product in good to excellent yields. Further applications in the late-stage olefination of some drugs, natural products, and fragrance-derived aryl ketones demonstrate the synthetic utility of this protocol. By employing ketone as both the directing group and the leaving group, 1,2-bifunctionalization is achieved via sequential ortho-C-H alkylation/ipso-Heck olefination.
- Wang, Mei-Ling,Xu, Hui,Li, Han-Yuan,Ma, Biao,Wang, Zhen-Yu,Wang, Xing,Dai, Hui-Xiong
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supporting information
p. 2147 - 2152
(2021/04/05)
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- Reduction of Electron-Deficient Alkenes Enabled by a Photoinduced Hydrogen Atom Transfer
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Direct hydrogen atom transfer from a photoredox-generated Hantzsch ester radical cation to electron-deficient alkenes has enabled the development of an efficient formal hydrogenation under mild, operationally simple conditions. The HAT-driven mechanism is supported by experimental and computational studies. The reaction is applied to a variety of cinnamate derivatives and related structures, irrespective of the presence of electron-donating or electron-withdrawing substituents in the aromatic ring and with good functional group compatibility. (Figure presented.).
- Larionova, Natalia A.,Ondozabal, Jun Miyatake,Cambeiro, Xacobe C.
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supporting information
p. 558 - 564
(2020/12/07)
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- A Photocatalytic Regioselective Direct Hydroaminoalkylation of Aryl-Substituted Alkenes with Amines
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A photocatalytic method for the α-selective hydroaminoalkylation of cinnamate esters has been developed. The reaction involves the regioselective addition of α-aminoalkyl radicals generated from aniline derivatives or aliphatic amines to the α-position of unsaturated esters. The scope of aromatic alkenes was extended to styrenes undergoing hydroaminoalkylation with anti-Markovnikov selectivity, which confirms the importance of the aromatic group at the β-position. Simple scale-up is demonstrated under continuous flow conditions, highlighting the practicality of the method.
- Larionova, Natalia A.,Ondozabal, Jun Miyatake,Smith, Emily G.,Cambeiro, Xacobe C.
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supporting information
p. 5383 - 5388
(2021/07/26)
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- HETEROCYCLIC COMPOUNDS FOR MODULATING NR2F6
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The present disclosure relates to compounds capable of modulating the activity of NR2F6. The compounds of the disclosure may be used in methods for the prevention and/or the treatment of diseases and disorders associated with modulating NR2F6 activity.
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Paragraph 00393; 00405
(2021/09/04)
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- Bis(imidazolium) chloride based on 1,2-phenylenediamine as efficient ligand precursor for palladium-catalyzed Mizoroki-Heck cross-coupling reaction
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Bis(imidazolium) chlorides based on 1,2-phenylenediamine were introduced as efficient ligand precursors in the Pd-catalyzed Mizoroki-Heck cross-coupling reactions of substituted aryl halides with activated alkenes to afford the corresponding functionalized alkenes. While high to excellent yields (78–96%) were obtained with aryl bromides, moderate yields (51–59%) were achieved for aryl chlorides in this protocol.
- Takallou, Ahmad,Habibi, Azizollah,Halimehjani, Azim Ziyaei,Balalaie, Saeed
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supporting information
p. 24 - 28
(2019/03/21)
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- Vinylogous Reactivity of Cyclic 2-Enones: Organocatalysed Asymmetric Addition to 2-Enals to Synthesize Fused Carbocycles
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A method for asymmetric and site selective annulations at the γ and γ′ positions of cyclic 2-enones with α,β-unsaturated aldehydes has been developed. The organocatalysed [3+3]-annulations proceed with high levels of regio-, diastereo-, and enantioselectivity, affording a series of high value fused carbocycles. Further elaboration gave key lactones (both bridged and fused).
- Sofiadis, Manolis,Kalaitzakis, Dimitris,Sarris, John,Montagnon, Tamsyn,Vassilikogiannakis, Georgios
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supporting information
p. 6742 - 6746
(2019/04/13)
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- Selective Palladium-Catalyzed Carbonylation of Alkynes: An Atom-Economic Synthesis of 1,4-Dicarboxylic Acid Diesters
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A class of novel diphosphine ligands bearing pyridine substituents was designed and synthesized for the first time. The resulting palladium complexes of L1 allow for chemo- and regioselective dialkoxycarbonylation of various aromatic and aliphatic alkynes affording a wide range of 1,4-dicarboxylic acid diesters in high yields and selectivities. Kinetic studies suggest the generation of 1,4-dicarboxylic acid diesters via cascade hydroesterification of the corresponding alkynes. Based on these investigations, the chemo- and regioselectivities of alkyne carbonylations can be controlled as shown by switching the ligand from L1 to L3 or L9 to give α,β-unsaturated esters.
- Liu, Jiawang,Dong, Kaiwu,Franke, Robert,Neumann, Helfried,Jackstell, Ralf,Beller, Matthias
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supporting information
p. 10282 - 10288
(2018/08/03)
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- Magnetic dendritic polymer nanocomposites as supports for palladium: A highly efficient and reusable catalyst for Mizoroki-Heck and Suzuki-Miyaura coupling reactions
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A novel catalyst Fe3O4@SiO2-Dendrimer-Pd based on palladium immobilized on magnetic dendritic polymer nanocomposites was successfully synthesized and characterized by FT-IR, EA, XRD, TEM, EDX, VSM and XPS. This nanocatalyst showed excellent catalytic activity for solvent-free Mizoroki-Heck reaction and Suzuki-Miyaura reaction in EtOH/H2O at a palladium loading of only 0.009 mol%. Moreover, the Fe3O4@SiO2-Dendrimer-Pd catalyst could be conveniently recovered by an external magnet and used consecutively five times with excellent yields. The remarkable catalytic performances and convenient magnetic separability of the Fe3O4@SiO2-Dendrimer-Pd catalyst make it promising for practical application.
- Ma, Rong,Yang, Pengbo,Bian, Fengling
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p. 4748 - 4756
(2018/03/21)
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- SUBSTITUTED DIHYDROPYRROLOPYRAZOLE COMPOUND
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Provided is a compound represented by formula (I) or a pharmacologically acceptable salt thereof: wherein L1 is an optionally substituted C1-6 alkylene group or the like, L2 is a single bond or the like, L3 is a single bond or the like, R1, R2, and R3 are each independently an optionally substituted C1-4 alkyl group or the like, R4 is a hydrogen atom or the like, and R5 is a hydrogen atom or the like.
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Paragraph 1051-1053
(2017/09/12)
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- Oxidative coupling of Michael acceptors with aryl nucleophiles produced through rhodium-catalyzed C-C bond activation
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Utilizing rhodium catalysis, aryl nucleophiles generated via carbon-carbon single bond activation successfully undergo oxidative coupling with Michael acceptors. The reaction scope encompasses a broad range of nucleophiles generated from quinolinyl ketones as well as a series of electron deficient terminal alkenes, illustrating the broad potential of intersecting carbon-carbon bond activation with synthetically useful coupling methodologies. The demonstrated oxidative coupling produces a range of cinnamyl derivatives, several of which are challenging to prepare via conventional routes.
- Gregerson, Caroline E.,Trentadue, Kathryn N.,Phipps, Erik J. T.,Kirsch, Janelle K.,Reed, Katherine M.,Dyke, Gabriella D.,Jansen, Jacob H.,Otteman, Christian B.,Stachowski, Jessica L.,Johnson, Jeffrey B.
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supporting information
p. 5944 - 5948
(2017/07/25)
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- Palladium supported on poly (ionic liquid) entrapped magnetic nanoparticles as a highly efficient and reusable catalyst for the solvent-free Heck reaction
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A novel palladium catalyst supported on poly (1-aminoethyl-3-vinylimidazolium bromide) entrapped magnetic nanoparticles (Pd/Fe3O4@PIL-NH2) was prepared. The catalyst was characterized by TEM, FT-IR, VSM, XRD, and XPS. The Pd loading on the catalyst was 0.23 wt % as measured by AAS. The catalyst showed excellent activity for the solvent-free Heck reaction. In addition, this novel Pd catalyst could be simply recovered with an external magnet and run five times with excellent yields achieved.
- Liu, Wendong,Wang, Dongfang,Duan, Yajing,Zhang, Yahui,Bian, Fengling
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supporting information
p. 1784 - 1789
(2015/03/30)
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- SULFAMATE DERIVATIVE COMPOUND FOR USE IN PREVENTING OR TREATING EPILEPSY
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The present invention relates to a pharmaceutical composition for treating or preventing epilepsy containing a sulfamate derivative compound and/or pharmaceutically acceptable salt thereof as an active ingredient. Furthermore, the present invention relates to a method for treatment or prevention epilepsy comprising administering a sulfamate derivative compound in a pharmaceutically effective amount to a subject in need of treatment or prevention of epilepsy.
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Page/Page column 50; 51
(2015/06/25)
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- Pd nanoparticles in the thermoregulated ionic liquid and organic biphasic system: An efficient and recyclable catalyst for heck reaction
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A thermoregulated ionic liquid and organic biphasic system composed of ionic liquid [CH3(OCH2CH2)16N +Et3][CH3SO3 -] (IL PEG750) with ILPEG750-stabilized Pd nanoparticles and organic solvents, which allows for not only a highly efficient homogeneous catalytic reaction, but also an easy biphasic separation and reuse of catalyst attributed to the thermoregulated phase-transition property of the system, was employed for Heck reaction. The ILPEG750-stabilized Pd nanoparticle catalyst exhibited high efficiency, more importantly, after reaction the Pd nanoparticle catalyst could be separated from products by simple phase separation and recycled for six times without evident loss of activity. Graphical Abstract: A thermoregulated ionic liquid and organic biphasic system containing [CH3(OCH2CH2)16N +Et3][CH3SO 3 - ] (ILPEG750)-stabilized Pd nanoparticles was applied to Heck reaction for the first time. The Pd nanoparticle catalyst exhibited high efficiency and good recyclability.[Figure not available: see fulltext.]
- Zeng, Yan,Wang, Yanhua,Xu, Yicheng,Song, Ying,Jiang, Jingyang,Jin, Zilin
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p. 200 - 205
(2013/03/13)
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- PHENYLALKYL SULFAMATE COMPOUND AND MUSCLE RELAXANT COMPOSITION COMPRISING THE SAME
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The present invention relates to novel phenylalkyl sulfamate compounds, a method for preventing or treating a disease associated with muscle spasm. The present invention ensures the enhancement of muscle relaxation activity essential for alleviation of muscle spasm, such that it is promising for preventing or treating various diseases associated with muscle spasm.
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Page/Page column 27-28; 54
(2014/01/08)
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- Oxygen and base-free oxidative heck reactions of arylboronic acids with olefins
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A mild and efficient protocol for palladium-catalyzed oxidative Heck reactions of arylboronic acids with both electron-rich and -deficient olefins is described. In contrast to the normal oxidative Heck coupling, this new method works in the absence of a base, oxygen, or other external oxidants. With a wide variety of substrates tolerated, the method broadens the scope of palladium-catalyzed coupling reactions. Copyright
- Ruan, Jiwu,Li, Xinming,Saidi, Ourida,Xiao, Jianliang
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p. 2424 - 2425
(2008/09/18)
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- New N-heterocyclic carbene palladium complex/ionic liquid matrix immobilized on silica: Application as recoverable catalyst for the Heck reaction
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A new concept of simultaneous covalent anchoring of a N-heterocyclic carbene palladium/ionic liquid matrix on the silica surface and the application of the resulting catalyst in the Heck reaction of a variety of different haloarenes is described. The catalyst shows high thermal stability (up to 280 °C) and could be recovered and reused for four reaction cycles, giving a total TON ? 36 600. Furthermore, TEM coupled with EDX analysis indicate the formation of Pd nanoparticles within the immobilized IL layer.
- Karimi, Babak,Enders, Dieter
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p. 1237 - 1240
(2007/10/03)
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- Synthesis of N-glyoxyl prolyl and pipecolyl amides and thioesters and evaluation of their in vitro and in vivo nerve regenerative effects
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The recent discovery that small molecule ligands for the peptidyl-prolyl isomerase (PPIase) FKBP12 possess powerful neuroprotective and neuroregenerative properties in vitro and in vivo suggests therapeutic utility for such compounds in neurodegenerative disease. The neurotrophic effects of these compounds are independent of the immunosuppressive pathways by which drugs such as FK506 and rapamycin operate. Previous work by ourselves and other groups exploring the structure-activity relationships (SAR) of small molecules that mimic only the FKBP binding domain portion of FK506 has focused on esters of proline and pipecolic acid. We have explored amide and thioester analogues of these earlier structures and found that they too are extremely potent in promoting recovery of lesioned dopaminergic pathways in a mouse model of Parkinson's disease. Several compounds were shown to be highly effective upon oral administration after lesioning of the dopaminergic pathway, providing further evidence of the potential clinical utility of a variety of structural classes of FKBP12 ligands.
- Hamilton, Gregory S.,Wu, Yong-Qian,Limburg, David C.,Wilkinson, Douglas E.,Vaal, Mark J.,Li, Jia-He,Thomas, Christine,Huang, Wei,Sauer, Hansjorg,Ross, Douglas T.,Soni, Raj,Chen, Yi,Guo, Hongshi,Howorth, Pamela,Valentine, Heather,Liang, Shi,Spicer, Dawn,Fuller, Mike,Steiner, Joseph P.
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p. 3549 - 3557
(2007/10/03)
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- N-substituted nonaryl-heterocyclic NMDA/NR2B antagonists
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Compounds represented by Formula (I): 1or pharmaceutically acceptable salts thereof, are effective as NMDA NR2B antagonists useful for relieving pain.
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- Aryl and cycloalkyl analogues of AMPA: Synthetic, pharmacological and stereochemical aspects
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We have previously shown that (RS)-2-amino-3-(3-hydroxy-5-phenylisoxazol-4-yl)propionic acid (APPA, 2) is a functional partial agonist at the (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) subtype of excitatory amino acid receptors, reflecting that (S)-APPA is a full agonist and (R)-APPA a competitive antagonist at AMPA receptors. We have now synthesized and pharmacologically characterized (RS)-2-amino-3-[3-hydroxy-5-(2-fluorophenyl)isoxazol-4-yl]propionic acid (2-F-APPA, 5a), 3-F-APPA (5b), 4-F-APPA (5c), (S)-4-F APPA (6), (R)-4-F-APPA (7), and the fully and partially, respectively, saturated APPA (2) analogues, (RS)-2-amino-3-(3-hydroxy-5-cyclohexylisoxazol-4-yl)propionic acid (5d) and compound 5e containing a 1-cyclohexenyl ring. The absolute stereochemistry of 6 and 7 was established on the basis of comparative circular dichroism studies on 6, 7, and (S)- and (R)-APPA. 4-F-APPA (5c), (S)-4-F-APPA (6), 5d, and 5e were shown to selectively inhibit [3H]AMPA binding and to activate AMPA receptors. Whereas (S)-4-F-APPA (6) showed full AMPA receptor agonism, (R)-4-F-APPA (7) was an AMPA receptor antagonist. Co-administration of (S)- and (R)-4-F-APPA to the rat cortical wedge preparation produced functional partial AMPA receptor agonism. Semi empirical calculations showed that the magnitude of the torsional angle of the bond connecting the two rings in the series of nonannulated bicyclic AMPA analogues appears to be of importance for the potency and efficacy of these compounds.
- Skjaerbaek, Niels,Brehm, Lotte,Johansen, Tommy N.,Hansen, Lene M.,Nielsen, Birgitte,Ebert, Bjarke,Soby, Karina K.,Stensbol, Tine B.,Falch, Erik,Krogsgaard-Larsen, Povl
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p. 119 - 131
(2007/10/03)
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- trans-2-Aryl-N,N-dipropylcyclopropylamines: Synthesis and interactions with 5-HT(1A) receptors
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Twelve N,N-dipropyl-substituted derivatives of trans-2- arylcyclopropylamine have been prepared and assayed for their ability to displace [3H]-8-OH-DPAT from rat brain 5-HT(1A) receptors. The new derivatives include phenyl (7a), bromo- (7b) and fluorophenyl (7c-e), 2- methoxy-5-fluorophenyl (7h), and 2-hydroxy-5-fluorophenyl (71) as well as trifluoromethylphenyl (7f) and 2,3-dichlorophenyl (7g) analogues. In the present series of compounds, electron-withdrawing substituents in the phenyl ring appear to decrease the affinity for 5-HT(1A) receptors. In contrast, electron-rich aryl groups, such as 2- or 3-thienyl (7j and 7k, respectively), provide compounds with high affinity. The additional bulk produced by the aromatic moiety in the 2-benzothienyl derivative 7i appears to be detrimental to 5-HT(1A) receptor affinity. The racemic mixtures of the interesting 7j and 7l were resolved into the enantiomers; 7j and 7l exhibited a high enantiomeric 5-HT(1A) receptor affinity ratio (75-fold and 100-fold, respectively). The enantiomers of 7j and 7l were evaluated in vivo by use of biochemical and behavioral tests in rats. Compound (1R,2R)-7j behaved as a partial agonist whereas (1R,2S)-7l appeared as an efficacious 5-HT(1A) receptor agonist, stimulating both autoreceptors and postsynaptic receptors.
- Vallgarda,Appelberg,Arvidsson,Hjorth,Svensson,Hacksell
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p. 1485 - 1493
(2007/10/03)
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