- Metal-Free Route for the Synthesis of 4-Acyl-1,2,3-Triazoles from Readily Available Building Blocks
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Functionalized 1,2,3-triazole heterocycles have been known for a long time and hold an extraordinary potential in diverse research areas ranging from medicinal chemistry to material science. However, the scope of therapeutically important 1-substituted 4-acyl-1H-1,2,3-triazoles is much less explored, probably due to the lack of synthetic methodologies of good scope and practicality. Here, we describe a practical and efficient one-pot multicomponent reaction for the synthesis of α-ketotriazoles from readily available building blocks such as methyl ketones, N,N-dimethylformamide dimethyl acetal, and organic azides with 100 % regioselectivity. This reaction is enabled by the in situ formation of an enaminone intermediate followed by its 1,3-dipolar cycloaddition reaction with an organic azide. We effectively utilized the developed strategy for the derivatization of various heterocycles and natural products, a protocol which is difficult or impossible to realize by other means.
- Thomas, Joice,Goyvaerts, Vince,Liekens, Sandra,Dehaen, Wim
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supporting information
p. 9966 - 9970
(2016/07/19)
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- DMF Dimethyl Acetal as Carbon Source for α-Methylation of Ketones: A Hydrogenation-Hydrogenolysis Strategy of Enaminones
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A novel heterogeneous catalytic hydrogenation-hydrogenolysis strategy has been developed for the α-methylation of ketones via enaminones using DMF dimethyl acetal as carbon source. This strategy provides a very convenient route to α-methylated ketones using a variety of ketones without any base or oxidant. (Chemical Equation Presented).
- Borah, Ashwini,Goswami, Limi,Neog, Kashmiri,Gogoi, Pranjal
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p. 4722 - 4728
(2015/05/13)
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- Highly fluorinated (σ-Aryl)-chelating titanium(IV) post-metallocene: Characterization and scalar [C-H???F-C] coupling
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The observation of weak intramolecular C-H???F-C interactions in group 4 (σ-aryl)-chelating complexes using NMR spectroscopic and neutron diffraction studies was recently reported. In this work, a new titanium(IV) catalyst precursor supported by a tridentate pyridine-2-phenolate-6-(σ-aryl) ligand, featuring a metal center surrounded by multiple CF3 substituents, has been synthesized. The nature of intramolecular interactions in the bis(benzyl) complex in solution was probed using multinuclear NMR spectroscopic experiments (including [ 1H,19F]-HMQC and -HMBC), which reveal scalar coupling across C-H???F-C interactions between methylene hydrogens and the proximal CF3 group on the σ-aryl (but not the phenolate) moiety. High activities are observed for ethylene polymerization at different temperatures, which exceed those for the tBu-phenolate congener.
- Liu, Cham-Chuen,So, Loi-Chi,Lo, Jerry C. Y.,Chan, Michael C. W.,Kaneyoshi, Hiromu,Makio, Haruyuki
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p. 5274 - 5281
(2012/11/07)
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- Facile synthesis of 6-aryl-3-cyanopyridine-2-(1H)-thiones from aryl ketones
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An improved synthesis of 6-aryl-3-cyanopyridine-2-(1H)-thiones utilizing enaminones as starting materials catalyzed by 1,4-diazabicyclo[2.2.2]octane (DABCO) was described. Moreover, a convenient one-pot conversion of aryl ketones to 6-aryl-3-cyanopyridine-2-(1H)-thiones was also developed in moderate to good yields (up to 80%). Copyright Taylor & Francis Group, LLC.
- Zheng, Ren-Lin,Zeng, Xiu-Xiu,He, Hai-Yun,He, Jun,Yang, Sheng-Yong,Yu, Luo-Ting,Yang, Li
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experimental part
p. 1521 - 1531
(2012/04/17)
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- Novel thienopyridine derivatives as specific anti-hepatocellular carcinoma (HCC) agents: Synthesis, preliminary structure-activity relationships, and in vitro biological evaluation
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Novel thienopyridine derivatives 1b-1r were synthesized, based on a hit compound 1a that was found in a previous cell-based screening of anticancer drugs. Compounds 1a-1r have the following features: (1) their anticancer activity in vitro was first reported by our group. (2) The most potent analog 1g possesses hepatocellular carcinoma (HCC)-specific anticancer activity. It can specifically inhibit the proliferation of the human hepatoma HepG2 cells with an IC50 value of 0.016 μM (compared with doxorubicin as a positive control, whose IC50 was 0.37 μM). It is inactive toward a panel of five different types of human cancer cell lines. (3) Compound 1g remarkably induces G0/G1 arrest and apoptosis in HepG2 cells in vitro at low micromolar concentrations. These results, especially the HCC-specific anticancer activity of 1g, suggest their potential in targeted chemotherapy for HCC.
- Zeng, Xiu-Xiu,Zheng, Ren-Lin,Zhou, Tian,He, Hai-Yun,Liu, Ji-Yan,Zheng, Yu,Tong, Ai-Ping,Xiang, Ming-Li,Song, Xiang-Rong,Yang, Sheng-Yong,Yu, Luo-Ting,Wei, Yu-Quan,Zhao, Ying-Lan,Yang, Li
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supporting information; experimental part
p. 6282 - 6285
(2010/12/18)
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