- 2,3-Dichloro-5,6-Dicyano-1,4-Benzoquinone (DDQ)-Mediated Tandem Oxidative Coupling/Intramolecular Annulation/Dehydro-Aromatization for the Synthesis of Polysubstituted and Fused Pyridines
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A DDQ-mediated tandem reaction of 1,3-diarylpropenes and β-enaminoesters/4-aminocoumarins is disclosed. It involves oxidative coupling, intramolecular annulation and dehydro-aromatization reaction, which provides an efficient and mild method for the synthesis of polysubstituted and fused pyridines under metal-free conditions. (Figure presented.).
- Cheng, Dongping,Deng, Zhiteng,Yan, Xianhang,Wang, Mingliang,Xu, Xiaoliang,Yan, Jizhong
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- Synthetic method of ethyl 2,4,6-triphenylnicotinate
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The invention discloses a synthetic method of ethyl 2,4,6-triphenylnicotinate. The method comprises the following steps of: reacting beta-enamine ester as shown in a formula I and 1,3-diphenyl propylene as shown in a formula II which are used as raw mater
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- Method for preparing polysubstituted pyridine
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The invention discloses a method for preparing polysubstituted pyridine. The method comprises the following steps: dissolving a 1,5-dicarbonyl compound into DMSO (dimethyl sulfoxide) in a stirring manner, weighing and adding an ammonium acetate solid into a solution of the DMSO at one time, and heating and stirring a mixed solution; checking whether reaction is completed or not by virtue of a thin layer chromatography plate, cooling the reacted mixed solution to room temperature, diluting the reacted mixed solution with ethyl acetate, and washing an ethyl acetate layer for 3 to 5 times with de-ionized water; evaporating an organic phase of the ethyl acetate layer to dryness under reduced pressure, and recrystallizing a concentrate with dichloromethane to prepare a 1,2,3,5-tetra-substituted pyridine product. According to the method, the DMSO is adopted as a solvent and an oxidant, and the 1,5-dicarbonyl compound is enabled to react with ammonium acetate to generate 1,2,3,5-tetra-substituted pyridine under a heating condition. A reaction system is simple, addition of an additional oxidant and the conditions of high temperature and intense heat are avoided, and the method is particularly suitable to a pyridine structure of which three positions are substituted with ester groups.
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Paragraph 0031; 0032; 0033; 0034; 0035; 0036
(2017/07/25)
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- One-Pot Reactions for Modular Synthesis of Polysubstituted and Fused Pyridines
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A 2-fluoro-1,3-dicarbonyl-initiated one-pot Michael addition/[5 + 1] annulation/dehydrofluorinative aromatization reaction sequence is introduced for regioselective synthesis of di-, tri-, tetra-, and pentasubstituted pyridines as well as fused pyridines. This simple and modular synthesis is performed using readily available starting materials and under transition-metal catalyst-free conditions.
- Song, Zhidong,Huang, Xin,Yi, Wenbin,Zhang, Wei
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supporting information
p. 5640 - 5643
(2016/11/17)
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- Highly functionalized pyridines synthesis from N-sulfonyl ketimines and alkynes using the N-S bond as an internal oxidant
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The N-S bond-based internal oxidant offers a distinct approach for the synthesis of highly functionalized pyridines. A novel Rh(III)-catalyzed one-pot process undergoes an efficient C-C/C-N bond formation along with desulfonylation under very mild conditions. The method is quite simple, general, and efficient.
- Zhang, Qian-Ru,Huang, Ji-Rong,Zhang, Wei,Dong, Lin
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p. 1684 - 1687
(2014/04/17)
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