- Three-Step One-Pot Process of 3-Methyl-5-Benzofuranol from Amine, Aldehydes, and p-Benzoquinone
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3-Methyl-5-benzofuranol was prepared by a one-pot process from morpholine, propionaldehyde, and p-benzoquinone in 85-87% isolated yields. Avoiding the tedious multistep isolation and purification operations, this practical and efficient process dramatically enhanced the production efficiency as well as reduced the amount of chemical wastes of reaction. The scale-up results showed that the performance was maintained, suggesting potential large-scale applications. Furthermore, the synthesis strategy showed high efficiency for a wide range of aliphatic aldehydes and ketone derivatives.
- Liang, Chaoming,Sun, Maolin,Shen, Xinyuan,Shan, Chao,Wang, Weijuan,Cheng, Ruihua,Ye, Jinxing
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p. 810 - 816
(2021/04/05)
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- Discovery of quinolone derivatives as antimycobacterial agents
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Tuberculosis (TB), an infectious disease caused byMycobacterium tuberculosis(M. tuberculosis), is an important public health issue. Current first-line drugs administered to TB patients have been in use for over 40 years, whereas second-line drugs display strong side effects and poor compliance. Additionally, designing effective regimens to treat patients infected with multi- and extremely-drug-resistant (MDR and XDR) strains of TB is challenging. In this report, we screened our compound library and identified compound1with antituberculosis activity and a minimal inhibitory concentration (MIC) againstM. tuberculosisof 20 μg mL?1. Structure optimization and the structure-activity relationship of1as the lead compound enabled the design and synthesis of a series of quinolone derivatives,6a1-6a2,6b1-6b36,6c1,6d1-6d14,7a1-7a2,7b1-7b2,7c1,8a1-8a5,9a1-9a4and10a1-10a6. These compounds were evaluatedin vitrofor anti-tubercular activity against theM. tuberculosisH37Rv strain. Among them, compounds6b6,6b12and6b21exhibited MIC values in the range of 1.2-3 μg mL?1and showed excellent activity against the tested MDR-TB strain (MIC: 3, 2.9 and 0.9 μg mL?1, respectively). All three compounds were non-toxic toward A549 and Vero cells (>100 and >50 μg mL?1, respectively). In addition, an antibacterial spectrum test carried out using compound6b21showed that this compound specifically inhibitsM. tuberculosis. These can serve as a new starting point for the development of anti-TB agents with therapeutic potential.
- Gao, Chao,Li, Xiao,Liu, Kun-Lin,Teng, Fei,Xiong, Lu,Yu, Luo-Ting
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p. 24095 - 24115
(2021/07/29)
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- Enantioselective N-Heterocyclic Carbene Catalysis via the Dienyl Acyl Azolium
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Herein we report the enantioselective N-heterocyclic carbene catalyzed (4+2) annulation of the dienyl acyl azolium with enolates. The reaction exploits readily accessible acyl fluorides and TMS enol ethers to give a range of highly enantio- and diastereo-enriched cyclohexenes (most >97:3 er and >20:1 dr). The reaction was found to require high nucleophilicity NHC catalysts with mechanistic studies supporting a stepwise 1,6-addition/β-lactonization.
- Gillard, Rachel M.,Fernando, Jared E. M.,Lupton, David W.
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supporting information
p. 4712 - 4716
(2018/03/27)
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- The hit-to-lead optimization of 1,2,3,4,4a,9a-hexahydro-1H-xanthenes as glucocorticoid receptor antagonists
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The structure-activity relationship (SAR) study of a 1,2,3,4,4a,9a- hexahydro-1H-xanthene series of selective, human glucocorticoid receptor α (hGRα) antagonists is reported. Compounds were screened using hydroxyapatite-based GR binding and MMTV-Luc co-transfection reporter gene assays. Four different regions of the scaffold were modified to assess the effects on hGRα antagonism and related potency. Compound 8d exhibits an 8-fold better bioactivity than the original hit 1a, as well as an improved chemical stability, which make it a promising lead for the subsequent optimization.
- Zhu, Yan-Hui,Zhang, Meng,Li, Qun-Yi,Liu, Qing,Zhang, Jie,Yuan, Yun-Yun,Nan, Fa-Jun,Wang, Ming-Wei
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supporting information
p. 693 - 698
(2014/06/09)
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- Thermal [2 + 2] cycloaddition of morpholinoenamines with C60 via a single electron transfer
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The thermal reaction of C60 with five- and six-membered morpholinocycloalkenes in refluxing toluene exclusively gave the [2 + 2] cycloadducts in high yields. However, a seven-membered homologue sluggishly reacted with C60 because of the increasing steric hindrance. This cycloaddition reaction is likely to proceed via a single electron transfer (SET), a radical-coupling, and subsequent ion cyclization rather than the prior proton transfer between the radical ions.
- Mikie, Tsubasa,Asahara, Haruyasu,Nagao, Kazuaki,Ikuma, Naohiko,Kokubo, Ken,Oshima, Takumi
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supporting information; experimental part
p. 4244 - 4247
(2011/10/08)
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- Base-promoted reactions of dichlorocarbene adducts of cyclic enamines: A new route to annulated pyrroles
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Treatment of the gem-dihalogenocyclopropanes 1-5 with potassium tert-butoxide or LDA results in the formation of the corresponding and annulated pyrroles 13-17, respectively.
- Bissember, Alex C.,Phillis, Andrew T.,Banwell, Martin G.,Willis, Anthony C.
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p. 5421 - 5424
(2008/09/17)
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- Synthesis of Enamines from Cycloalkanones and Secondary Cyclic Amines using K-10 Montmorillonite Clay
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The synthesis of enamines from cycloalkanones and secondary cyclic amines has been carried out in 85-95percent yield in the presence of K-10 montmorrilonite clay and with azeotropic removal of the water formed in the condensation.
- Dewan, Sharwan K.,Varma, Urmila,Malik, Shiv Darshan
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- Lanthanoid(III) Trichloride-Tin(II) Chloride mediated Cycloaddition Reaction of α,α'-Dibromo Ketones with 1,3-Dienes or Enamines
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The reaction of α,α'-dibromo ketones with 1,3-dienes in the presence of CeCl3-SnCl2 in tetrahydrofuran is found to give the corresponding cycloadduct in fair to good yields under mild conditions.Furan and cyclopentadiene serve as highly efficient receptors of the oxallyl intermediate to give bicyclic cycloadducts.The reaction of 2,4-dibromo-3-pentanone with isoprene gives both and cycloadducts. Cycloaddition proceeds similarly with enamines to afford 2-cyclopenten-1-ones after treatment with 3percent ethanolic NaOH solution.
- Fukuzawa, Shin-ichi,Fukushima, Masakazu,Fujinami, Tatsuo,Sakai, Shizuyoshi
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p. 2348 - 2352
(2007/10/02)
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- On the Electrochemical Oxidation of Enamines
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The electrochemical properties of enamines of the cyclic ketones cyclo-pentanone, -hexanone, -heptanone, and -octanone with the cyclic amines pyrrolidine, piperidine, 1-methylpiperazine (1-MP), morpholine (MO), hexa-, and hepta-methyleneimine are investigated with the aid of cyclic voltammetry.The oxidations are totally irreversible.The lifetime of the intermediate cation radicals are shorter than 0.2 ms as determined by double potential step chronoamperometry.The anodic peak potentials depend on the amine component in the order of ring sizes 57; 861-MPMO.The variation of the ketone component shows no significant influence on the peak potentials.The ionization potentials of the enamines were measured and correlated with the anodic peak potentials.
- Schoeller, Wolfgang W.,Niemann, Juergen,Rademacher, Paul
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p. 369 - 374
(2007/10/02)
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- The Chemistry of Aryllead(IV) Tricarboxylates. Reaction with Enamines
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The treatment of 1-morhpholinocyclopentene (1a) with p-methoxyphenyllead triacetate (2a) in chloroform provides a simple high-yielding route to 2-(4-methoxyphenyl)cyclopentanone (3a).This arylation reaction of enamines has been investigated with a variety of substrates and a number of aryllead triacetates.The reaction has been found to be very sensitive to steric effects and is thus a useful synthetic method in a relatively small number of cases.Acetoxylation is a major competing reaction with those enamines of cyclic ketones which give a low to moderate yield of arylated product.
- May, George L.,Pinhey, John T.
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p. 1859 - 1871
(2007/10/02)
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