- Regiocontrolled synthesis of 2,4,6-triarylpyridines from methyl ketones, electron-deficient acetylenes and ammonium acetate
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A novel one-pot two-step approach for the synthesis of 2,4,6-triarylpyridinesvia t-BuOK/DMSO-promotedC-vinylation of a variety of methyl ketones with electron-deficient acetylenes (alkynones) followed by a cyclization of thein situgenerated unsaturated 1,5-dicarbonyl species with ammonium acetate has been developed. This approach possesses competitive advantages such as high regioselectivity, available starting materials and the absence of transition-metal catalysts, oxidants and undesirable byproducts. A wide synthetic utility of the developed approach was demonstrated by the synthesis of trisubstituted, tetrasubstituted and fused pyridines.
- Shabalin, Dmitrii A.,Dvorko, Marina Yu.,Schmidt, Elena Yu.,Trofimov, Boris A.
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supporting information
p. 2703 - 2715
(2021/04/07)
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- Method for synthesizing polysubstituted pyridine derivative based on oxime ester and unsaturated ketone under catalysis of ferric salt
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The invention belongs to the technical field of organic synthesis, and particularly relates to a method for synthesizing a polysubstituted pyridine derivative based on oxime ester and unsaturated ketone under the catalysis of ferric salt. For the first ti
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Paragraph 0054-0057
(2020/06/02)
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- Synthesis of triphenylpyridines: Via an oxidative cyclization reaction using Sr-doped LaCoO3 perovskite as a recyclable heterogeneous catalyst
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An La0.6Sr0.4CoO3 strontium-doped lanthanum cobaltite perovskite was prepared via a gelation and calcination approach and used as a heterogeneous catalyst for the synthesis of triphenylpyridines via the cyclization reactio
- Le, Thu N. M.,Doan, Son H.,Pham, Phuc H.,Trinh, Khang H.,Huynh, Tien V.,Tran, Tien T. T.,Le, Minh-Vien,Nguyen, Tung T.,Phan, Nam T. S.
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p. 23876 - 23887
(2019/08/12)
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- A New Synthetic Pathway to Triphenylpyridines via Cascade Reactions Utilizing a New Iron-Organic Framework as a Recyclable Heterogeneous Catalyst
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A new iron-organic framework, VNU-22 {[Fe3(BTC)(BPDC)2]·11.97H2O}, constructed from BTC3–, BPDC2– pillars and infinite [Fe3(CO2)7]∞ rod SBU, was obtained. The VNU-22 was utilized as a heterogeneous catalyst in the synthesis of 2,4,6-triphenylpyridines via cascade reactions from acetophenones and phenylacetic acids with ammonium acetate as a nitrogen source. This transformation is new. The VNU-22 was more active in the cascade reactions than many homogeneous and heterogeneous catalysts. The framework catalyst was recovered and reutilized without an appreciable decline in its performance. To our best knowledge, this synthetic pathway to 2,4,6-triphenylpyridines was not previously reported, and would attract interests from the chemical industry.
- Doan, Son H.,Tran, Nhu K. Q.,Pham, Phuc H.,Nguyen, Vu H. H.,Nguyen, Ngoc N.,Ha, Phuong T. M.,Li, Shuang,Le, Ha V.,Le, Nhan T. H.,Tu, Thach N.,Phan, Nam T. S.
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supporting information
p. 2382 - 2389
(2019/03/27)
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- A new route to triphenylpyridines utilizing ketoximes as building blocks via cascade reactions under iron-organic framework catalysis
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Iron-based metal–organic framework VNU-20 was utilized as a heterogeneous catalyst for cascade reactions between ketoximes and dibenzyl ether to produce 2,4,6-triphenylpyridines. Additionally, benzyl alcohol and (dimethoxymethyl)benzene could be used as an alternative starting materials for the transformation. The oxidant exhibited a remarkable impact on the reactions, and di-tert-butylperoxide was the most appropriate candidate. The VNU-20 displayed higher efficiency than many homogeneous and heterogeneous catalysts. The catalyst was reusable for the cascade reactions without a noticeable deterioration in catalytic activity. This transformation is new, and would offer alternative routes to triphenylpyridines utilizing ketoximes as building blocks.
- Nguyen, Vu H.H.,Doan, Son H.,Van, Tram T.,Pham, Phuc H.,Nguyen, Tran T.N.,Nguyen, Ngoc N.,Tu, Thach N.,Phan, Nam T.S.
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- C6-Selective Direct Arylation of 2-Phenylpyridine via an Activated N-methylpyridinium Salt: A Combined Experimental and Theoretical Study
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An elegant pre-activation strategy, based on the formation of N-methylpyridinium iodide salts for C6-selective direct arylation of 2-phenylpyridines using Pd/Cu cooperative catalysis, has been developed. By this methodology, a wide range of unsymmetrical 2, 6-diarylpyridines were synthesized with high reactivity and regioselectivity as well as good functional group tolerance. In particular, challenging substrates bearing electron donating groups (EDGs), such as OMe, NMe2, were also successfully employed in this reaction. Deuterium incorporation studies revealed that the C?H bond acidity is improved significantly in N-methylpyridinium salts compared with their N-Oxide and N-iminopyridinium ylide counterparts, thus solving the long-standing problem associated with previous strategies for the synthesis of diaryl pyridines. Finally, the control experiments and DFT calculations supported a Pd-catalyzed and Cu-mediated mechanism in which a carbenoid copper species that is formed in-situ from N-methylpyridinium salts, participates in a Pd-catalyzed arylation followed by an iodide-promoted N-demethylation process. (Figure presented.).
- Yin, Changzhen,Zhong, Kangbao,Li, Wenjing,Yang, Xiao,Sun, Rui,Zhang, Chunchun,Zheng, Xueli,Yuan, Maolin,Li, Ruixiang,Lan, Yu,Fu, Haiyan,Chen, Hua
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supporting information
p. 3990 - 3998
(2018/09/12)
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- Multi-substituted pyridine derivative and its preparation method
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The invention discloses a polysubstituted pyridine derivative and a preparation method thereof. The derivative has a structure as shown in specification, wherein R1, R2, R3, R4 and R5 all are any one selected from hydrogen atom, halogen atom, alkyl, aryl, substituted aryl, acyl, amino, nitryl and alkoxy; the invention also discloses a preparation method of the polysubstituted pyridine derivative; the preparation method comprises the following steps: by taking acetyenic ketone and 1-arylethylamine as raw materials, and under the action of appropriate alkali, heating to have a reaction in the solvent to obtain the polysubstituted pyridine derivative as shown in the formula at high yield. The preparation method is mild in reaction condition, short in reaction time, wide in substrate range, high in reaction specifity, high in yield and simple in after-treatment.
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Paragraph 0056; 0057; 0058; 0059
(2018/01/20)
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- An aminocatalyzed michael addition/Iron-Mediated decarboxylative cyclization sequence for the preparation of 2,3,4,6-Tetrasubstituted pyridines: Scope and mechanistic insights
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A novel, scalable strategy for the preparation of 2,3,4,6-tetrasubstituted pyridines is described. This protocol has two steps: an aminocatalyzed addition of ketones to alkylidene isoxazol-5-ones, followed by an iron-mediated decarboxylative cyclization event. Mechanistic insights for both steps are provided based on HRMS-ESI(+) studies.
- Stivanin, Mateus L.,Duarte, Marcelo,Sartori, Camila,Capreti, Naylil M.R.,Angolini, Celio F.F.,Jurberg, Igor D.
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p. 10319 - 10330
(2018/04/20)
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- Synthesis of Highly Substituted Pyridines through Copper-Catalyzed Condensation of Oximes and α,β-Unsaturated Imines
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A copper-catalyzed condensation reaction of oxime acetates and α,β-unsaturated ketimines to give pyridine derivatives is reported. The reaction features mild conditions, high functional-group compatibility, and high regioselectivity with respect to unsymmetrical oxime acetates, thus allowing the preparation of a wide range of polysubstituted pyridines, many of which are not readily accessible by conventional condensation methods.
- Tan, Wei Wen,Ong, Yew Jin,Yoshikai, Naohiko
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supporting information
p. 8240 - 8244
(2017/06/30)
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- Acid-catalyzed tandem reaction for the synthesis of pyridine derivatives via C=C/C(sp3)-N bond cleavage of enones and primary amines
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A one-pot acid-catalyzed tandem reaction has been developed without any metallic reagents or extra oxidants. This reaction involves a C=C bond cleavage of enones via a “masked” reverse Aldol reaction, and C(sp3)-N bond cleavage of primary amines to provide nitrogen sources for the assembly of pyridine derivatives in high yields with excellent functional group tolerance.
- Mao, Zhong-Yuan,Liao, Xiao-Yun,Wang, Heng-Shan,Wang, Chun-Gu,Huang, Ke-Bin,Pan, Ying-Ming
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p. 13123 - 13129
(2017/03/11)
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- Copper(II) supported on magnetic chitosan: A green nanocatalyst for the synthesis of 2,4,6-triaryl pyridines by C-N bond cleavage of benzylamines
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In this paper, Cu/magnetic chitosan has been synthesized and used as a new green nanocatalyst for highly efficient synthesis of 2,4,6-triaryl pyridines via C-N bond cleavage of benzylamines under aerobic oxidation at 90 °C. The chemical and structural properties of the synthesized catalyst were determined by scanning electron microscopy, energy-dispersive X-ray, X-ray powder diffraction, thermogravimetric analysis and flame atomic absorption spectroscopies. It is found that the catalyst can be easily separated from the reaction mixture by an external magnetic field and recycled several times without a significant loss in activity.
- Shaabani, Ahmad,Borjian Boroujeni, Mahmoud,Laeini, Mohmmad Sadegh
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p. 27706 - 27713
(2016/03/30)
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- Base-Promoted β-C(sp3)-H Functionalization of Enaminones: An Approach to Polysubstituted Pyridines
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A convenient one-pot base-promoted synthesis of polysubstituted pyridines from 1-arylethylamines and ynones through the direct β-C(sp3)-H functionalization of enaminones under metal-free conditions has been developed. An intermolecular Michael addition reaction and an intramolecular condensation were involved in this procedure, which features high regioselectivity, high efficiency, and environmental friendliness. Various polysubstituted pyridines were provided in up to 92% yield for 34 examples.
- Shen, Jinhai,Cai, Dingding,Kuai, Changsheng,Liu, Yunqi,Wei, Ming'E,Cheng, Guolin,Cui, Xiuling
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p. 6584 - 6589
(2015/10/06)
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- Microwave-assisted, solvent-free, three-component synthesis of 2,4,6-triarylpyridines from benign components
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2,4,6-Triarylpyridine derivatives were synthesised by the reaction of guanidine with an acetophenone and a chalcone. These reactions were carried out as economical one-pot reactions under green conditions: no catalyst and solvent free.
- Zomordbakhsh, Shahab,Anaraki-Ardakani, Hossein,Zeeb, Mohsen,Sadeghi, Mahdi,Mazraeh-Seffid, Manouchehr
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experimental part
p. 138 - 140
(2012/09/22)
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- Microwave-promoted and Lewis acid catalysed synthesis of 2,4,6-triarylpyridines using urea as benign source of ammonia
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An efficient method for the synthesis of 2,4,6-triarylpyridines via microwave-promoted and BF3·OEt2-catalysed one-pot reaction of ω-pyrrolidinoacetophenone with chalcone is reported. This method illustrates urea as an environmentally
- Borthakur, Moyurima,Dutta, Mandakini,Gogoi, Shyamalee,Boruah, Romesh C.
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body text
p. 3125 - 3128
(2009/06/06)
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- A novel and efficient 2,4,6-trisubstituted pyridine ring synthesis via α-benzotriazolyl ketones
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Reaction of α-benzotriazolyl ketones with α,β-unsaturated ketones resulted in 2,4,6-triarylpyridines, 2,4-diaryl-5H-indeno[1,2-b]pyridines and 2,4-diaryl-5,6-dihydrobenzo[h]quinolines in good yields.
- Katritzky, Alan R.,Abdel-Fattah, Ashraf A. A.,Tymoshenko, Dmytro O.,Essawy, Samy A.
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p. 2114 - 2118
(2007/10/03)
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- A 'one pot' synthesis of polysubstituted pyridines from metallated alkylphosphonates, nitriles and α,β-unsaturated ketones
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A simple and efficient synthesis of polysubstituted pyridines is described. The key step is based on the regioselective addition of lithiated β-enaminophosphonates 5 to unsaturated carbonyl compounds 3. Pyridines 1 can also be obtained in 'one pot' reaction from phosphonates 6 when these compounds are metallated followed by addition of nitriles and unsaturated carbonyl compounds.
- Palacios, Francisco,Ochoa De Retana, Ana M. Ochoa,Oyarzabal, Julen
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p. 4577 - 4580
(2007/10/03)
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- Pyrylium Compounds. XXI. - Structure and Tautomerism of Pseudobases of Unsymmetrically Substituted 2,4,6-Triarylpyrylium Salts
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Hydrolytic ring opening of unsymmetrically substituted 2,4,6-triarylpyrylium salts 11 results in a mixture of two tautomeric pseudobases, the penten-1,5-diones 13 and 14.In crystalline state as a rule one of these tautomers markedly predominates, whereas
- Fischer, Gerhard W.,Herrmann, Michael
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p. 287 - 302
(2007/10/02)
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