- Sulfonated poly(ether sulfone)s containing pyridine moiety for PEMFC
-
Sulfonated poly(ether sulfone)s with varied degree of sulfonation (DS) were prepared via post-sulfonation of synthesized pyridine based poly(ether sulfone) (PPES) using concentrated sulfuric acid as sulfonating agent. The DS was varied with different mole ratio of 4,4′-(2, 2-diphenylethenylidene)diphenol, DHTPE in the polymer unit. PPES copolymers were synthesized by direct polycondensation of pyridine unit with bis-(4-fluorophenyl)-sulfone, 4,4′-ulfonyldiphenol and DHTPE. The structure of the resulting PPES copolymer membranes with different sulfonated units were studied by 1H NMR spectroscopy and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymer with water. The ion exchange capacity (IEC) and proton conductivity were evaluated according to the increase of DS. The water uptake (WU) of the resulting membranes was in the range of 17-58%, compared to that of Nafion 211, 28%. The membranes provided proton conductivities of 65-95 mS/cm in contrast to 103 mS/cm of Nafion 211.
- Jang, Hohyoun,Islam, Md. Monirul,Lim, Youngdon,Hossain, Md. Awlad,Cho, Younggil,Joo, Hyunho,Kim, Whangi,Jeon, Heung-Seok
-
-
Read Online
- A Facile and Green Synthesis of 2,4,6-Triarylpyridine Derivatives Using the Modified Mesoporous Organic Polymer Based on Calix [4]Resorcinarene: As an Efficient and Reusable Heterogeneous Acidic Catalyst
-
Abstract: The work describes an efficient one-pot synthesis of 2,4,6-trisubstituted pyridine derivatives through a three-component catalytic reaction. The procedure involves mesoporous organic polymer based on calix[4]resorcinarene in and functionalized b
- Mouradzadegun,Mostafavi,Ganjali
-
-
Read Online
- Synthesis of Kr?hnke pyridines through iron-catalyzed oxidative condensation/double alkynylation/amination cascade strategy
-
An efficient protocol for the synthesis of symmetrical and unsymmetrical 2,4,6-trisubstituted pyridines via oxidative cascade annulation of arylacetylenes with benzylamines has been developed. The reaction proceeds smoothly utilizing iron(II) triflate as a catalyst and molecular oxygen as an oxidant with broad substrate scope. Mechanistic studies reveal that the reaction may be experiences an oxidative condensation followed by double alkynylation and amination process.
- Gopalaiah, Kovuru,Choudhary, Renu
-
supporting information
(2021/09/15)
-
- Pyridine Skeleton Synthesis Using Acetonitrile as C4N1 Units and Solvent
-
The first [3 + 2 + 1] methodology for pyridine skeleton synthesis via cascade carbopalladation/cyclization of acetonitrile, arylboronic acids, and aldehydes was developed. This reaction proceeds via six step tandem reaction sequences involving the carbopalladation reaction of acetonitrile, a nucleophilic addition, a condensation, an intramolecular Michael addition, cyclization, and aromatization. Delightfully, both palladium acetate and supported palladium nanoparticles catalyzed this reaction with similar catalytic performance. The characterization results of the fresh and used supported palladium nanoparticle catalysts indicated that the reaction might be performed via a Pd(0)/Pd(II) catalytic cycle that began with Pd(0). Furthermore, the products showed good fluorescence characteristics. The green homogeneous/heterogenous catalytic methodologies pave a new way for constructing the pyridine skeleton.
- Bai, Chaolumen,Guo, Huifang,Liu, Xin,Liu, Dan,Sun, Zhaorigetu,Bao, Agula,Baiyin, Menghe,Muschin, Tegshi,Bao, Yong-Sheng
-
p. 12664 - 12675
(2021/09/18)
-
- Copper-catalyzed efficient access to 2,4,6-triphenyl pyridinesviaoxidative decarboxylative coupling of aryl acetic acids with oxime acetates
-
An efficient and concise approach for the synthesis of 2,4,6-triphenyl pyridines has been developed through copper-catalysed oxidative decarboxylative coupling of C(sp3) aryl acetic acids with oxime acetates in DMF at 150 °C under an oxygen atm
- Bharat Kumar, Karasala,Chinnari, Lekkala,Shyamala, Pulipaka,Siddaiah, Vidavalur,Varaprasad, Bodala
-
supporting information
p. 15205 - 15209
(2021/09/06)
-
- A new route to triphenylpyridines utilizing ketoximes as building blocks via cascade reactions under iron-organic framework catalysis
-
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.
-
-
- An efficient one pot three-component synthesis of 2,4,6-triarylpyridines using triflimide as a metal-free catalyst under solvent-free conditions
-
A simple and efficient protocol developed for one pot three-component synthesis of 2,4,6-triarylpyridines from aromatic aldehydes, substituted acetophenones and ammonium acetate using the versatile super Br?nsted acid triflimide (HNTf2) as an effective catalyst is described. The reactions proceed well in the presence of 1 mol% of HNTf2 at 80 °c under solvent-free conditions and provide the corresponding triarylpyridines in good to excellent yields. The method reported has several advantages such as a metal-free and commercially available catalyst, mild reaction conditions and lower loading of catalyst.
- Wang, Hongshe,Zhao, Weixing,Du, Juan,Wei, Fenyan,Chen, Qi,Wang, Xiaomei
-
p. 5158 - 5163
(2019/02/27)
-
- Cationic organotin cluster [t-Bu2Sn(OH)(H2O)]2 2+2OTf?-catalyzed one-pot three-component syntheses of 5-substituted 1H-tetrazoles and 2,4,6-triarylpyridines in water
-
The cationic organotin cluster [t-Bu2Sn(OH)(H2O)]2 2+2OTf? is easy to prepare and stable in air. The catalytic activity of [t-Bu2Sn(OH)(H2O)]2 2+2OTf? as a neutral organotin Lewis acid catalyst is probed through the one-pot three-component syntheses of 5-substituted 1H-tetrazoles from aldehydes, hydroxylamine hydrochloride and sodium azide, and of 2,4,6-triarylpyridines from aromatic aldehydes, substituted acetophenones and ammonium acetate. The reactions proceed well in the presence of 1?mol% of [t-Bu2Sn(OH)(H2O)]2 2+2OTf? in water and provide the corresponding 5-substituted 1H-tetrazoles and 2,4,6-triarylpyridines in good to excellent yields. The method reported has several advantages such as the catalyst being neutral, low catalyst loading and use of water as a green solvent.
- Wang, Hongshe,Zhao, Weixing,Du, Juan,Wei, Fenyan,Chen, Qi,Wang, Xiaomei
-
-
- B(C6F5)3-catalyzed oxidative deamination/cyclization cascade reaction of benzylamines and ketones for the synthesis of 2,4,6-triarylpyridines
-
The B(C6F5)3-catalyzed oxidative deamination/cyclization cascade reaction of benzylamines and ketones for the construction of 2,4,6-triarylpyridines under metal-/solvent-free conditions has been successfully achieved. The advantages of this strategy include good functional group tolerance, low catalyst loading and high yields.
- Ling, Fei,Shen, Leixin,Pan, Zhentao,Fang, Lu,Song, Dingguo,Xie, Zhen,Zhong, Weihui
-
supporting information
p. 3678 - 3682
(2018/09/11)
-
- Preparation method of 2,4,6-triaryl substituted pyridine derivative
-
The invention discloses a preparation method of a 2,4,6-triaryl substituted pyridine derivative. The preparation method comprises the following steps: taking a aryl methyl ketone compound and a benzylamine derivative as raw materials, taking tri(pentafluorobenzene)borane as a catalyst, and reacting for 6-24 hours under the oxygen condition at 80-160 DEG C to obtain the 2,4,6-triaryl substituted pyridine derivative. According to the preparation method has the main beneficial effects that the reaction raw materials are easily available; the consumption of the catalyst can be as low as 0.5%; theexperiment operation is simple; the target compound can be prepared by a one-pot process; the substrate universality is high; the 2,4,6-triaryl substituted pyridine derivative with different substituent groups can be built; the further derivatization research can be facilitated.
- -
-
Paragraph 0020
(2018/09/12)
-
- I2-Triggered N-O cleavage of ketoxime acetates for the synthesis of 3-(4-pyridyl)indoles
-
A facile and complementary [3 + 2 + 1] annulation of aryl ketoxime acetates and 3-formylindoles to give pyridine derivatives is reported. The condensation reaction demonstrated that I2 was capable of triggering N-O bond cleavage of ketoxime ace
- Gao, Qinghe,Wang, Yakun,Wang, Qianqian,Zhu, Yanping,Liu, Zhaomin,Zhang, Jixia
-
p. 9030 - 9037
(2018/12/10)
-
- Solid acid catalyst TS-1 zeolite-assisted solvent-free one-pot synthesis of poly-substituted 2,4,6-triaryl-pyridines
-
Abstract: A new method is described for one-pot solvent-free synthesis of 2,4,6-triaryl pyridines in the presence of a solid acid catalyst, titanium silicate (TS-1) via cyclocondensation of acetophenone, aryl aldehyde and ammonium acetate. The present method illustrates several advantages, such as eco-friendly reaction conditions, simplicity, short reaction time (3?h), easy separation of catalyst and high yields of the products (85–93%). Furthermore, the TS-1 catalyst was reused for four catalytic cycles with consistent catalytic activity. Graphical Abstract: [Figure not available: see fulltext.].
- Gadekar, Sachin P.,Lande, Machhindra K.
-
p. 3267 - 3278
(2018/02/06)
-
- Acid-catalyzed tandem reaction for the synthesis of pyridine derivatives via C=C/C(sp3)-N bond cleavage of enones and primary amines
-
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
-
p. 13123 - 13129
(2017/03/11)
-
- Metal-Free Synthesis of 2,4,6-Trisubstituted Pyridines via Iodine-Initiated Reaction of Methyl Aryl Ketones with Amines under Neat Heating
-
A neat heating protocol has been developed for metal-free synthesis of various 2,4,6-trisubstituted pyridines via iodine-initiated (in situ generated HI-catalyzed) condensation of methyl aryl ketones with amines and the following cyclization-aerobic oxidation. Large-scale synthesis and mechanistic investigation were also performed.
- Xu, Hui,Zeng, Ji-Chao,Wang, Fang-Jian,Zhang, Ze
-
supporting information
p. 1879 - 1883
(2017/04/06)
-
- Synthesis of symmetrical pyridines by iron-catalyzed cyclization of ketoxime acetates and aldehydes
-
A novel and facile iron-catalyzed cyclization of ketoxime acetates and aldehydes for the green synthesis of substituted pyridines has been developed. In the presence of a FeCl3 catalyst, this reaction exhibited a good functional group tolerance to produce 2,4,6-triarylsubstituted symmetrical pyridines in high yields in the absence of any additive. A gram-scale reaction sequence was performed to demonstrate the scaled-up applicability of this synthetic method.
- Yi, Yukun,Zhao, Mi-Na,Ren, Zhi-Hui,Wang, Yao-Yu,Guan, Zheng-Hui
-
p. 1023 - 1027
(2017/08/18)
-
- Microwave assisted one-pot pseudo four-component synthesis of 2,4,6-trisubstituted pyridines using γ-MnO2 nanoparticles
-
This work described an efficient, one-pot pseudo four-component synthesis of 2,4,6-triarylpyridines. This reaction was performed under microwave irradiation and solvent-free conditions in the presence of γ-MnO2 nanoparticles. Herein 2,4,6-triarylpyridines were synthesized via a simple reaction between benzyl alcohols, acetophenone, and ammonium acetate in the presence of γ-MnO2 nanoparticles in good to excellent yields. Eco friendly, excellent yields of the product, short reaction times, inexpensive and readily available starting material are the main advantages of this method. Graphical abstract: [Figure not available: see fulltext.]
- Mohammadi, Bagher
-
p. 1939 - 1943
(2016/10/21)
-
- Synthesis of Polyfunctional Pyridines via Copper-Catalyzed Oxidative Coupling Reactions
-
An efficient and concise approach for the synthesis of polysubstituted pyridines has been achieved through copper-catalyzed oxidative sp3 C-H coupling of oxime acetates with toluene derivatives. Besides, benzylamine and p-toluenesulfonylhydrazo
- Fu, Yajie,Wang, Panpan,Guo, Xin,Wu, Ping,Meng, Xu,Chen, Baohua
-
p. 11671 - 11677
(2016/12/09)
-
- An Efficient Synthesis of 2,4,6-Triarylpyridines by Use of Benzyl Halides under Neat Conditions
-
An efficient synthesis of 2,4,6-triarylpyridines is described. Heating a mixture of an acetophenone, a benzyl halide, and ammonium acetate under neat conditions afforded the corresponding Kr?hnke pyridines in excellent yields.
- Adib, Mehdi,Ayashi, Neda,Mirzaei, Peiman
-
p. 417 - 421
(2016/02/09)
-
- Synthesis of 2,4,6-Trisubstituted Pyridines by Oxidative Eosin y Photoredox Catalysis
-
Eosin Y, an organic dye, was activated as a photoredox catalyst in the presence of molecular oxygen using visible light and, when it was used in the reaction of aryl ketones and benzyl amines, afforded good yields (52-87%) of 2,4,6-triarylpyridines (21 examples) at ambient temperature. The aryl groups at the 2- and 6-positions are derived from ketones, while benzyl amine plays the dual role of providing an aryl functionality at the 4-position of pyridine as well as being a nitrogen donor.
- Rohokale, Rajendra S.,Koenig, Burkhard,Dhavale, Dilip D.
-
p. 7121 - 7126
(2016/08/30)
-
- Synthesis of a functionalized polymer based on a calix[4]resorcinarene via covalently anchored cationic moieties: A reactive solid support for ring transformation and expansion of thiopyrylium salts
-
In this work, for the first time, a cationic polymer containing pendant pyridinium groups was synthesized via post-functionalization of the polymeric backbone based on a calix[4]resorcinarene, and characterized by AFM, TEM, analytical CHN, TGA, and DTG te
- Mouradzadegun, Arash,Elahi, Somayeh,Abadast, Fatemeh
-
supporting information
p. 630 - 640
(2015/06/18)
-
- A Highly Efficient and Eco-Friendly Approach for the Synthesis of Triarylpyridine and Novel Triaryl-[1,3]Thiazepine Derivatives Via Ring Transformation and Expansion of Triarylthiopyrylium Salts
-
The paper reports, for the first time, thermally induced ring transformation and expansion of triarylthiopyrylium salts using a novel task-specific dicationic ionic liquid [1,1′-(butane-1,4-diyl)-bis(3-methylimidazolium)] diazide as a nucleophi
- Mouradzadegun, Arash,Elahi, Somayeh,Ghanbarzadeh, Parastoo
-
p. 2031 - 2039
(2015/12/12)
-
- An improved and highly efficient one-pot three-component synthesis of 2,4,6-triarylpyridines catalyzed by melamine trisulfonic acid under solvent-free condition
-
A facile one-pot synthesis of triarylpyridines as valuable products is reported via three-component condensation reaction in the presence of environmentally benign melamine trisulfonic acid (MTSA) under solvent-free condition. The present protocol offers several advantages including simple work-up procedure, high yields and ease of catalyst isolation with suitable recyclability.
- Mouradzadegun, Arash,Kiasat, Ali Reza,Asareh, Hadi
-
p. 943 - 947
(2016/02/18)
-
- Three-component one-pot synthesis of 2,4,6-triarylpyridines without catalyst and solvent
-
An efficient and green synthesis of 2,4,6-triarylpyridines by a one-pot three-component condensation of aromatic aldehydes, substituted acetophenones, and ammonium acetate without catalyst at 130°C under solvent-free conditions is described. This method offers several advantages such as simple procedure, easy work-up, short reaction time, low cost, environmentally friendly conditions, and moderate to high yields.
- Wang, Min,Yang, Zhongyong,Song, Zhiguo,Wang, Qinglin
-
p. 907 - 910
(2015/05/13)
-
- Copper-catalyzed formal C-N bond cleavage of aromatic methylamines: Assembly of pyridine derivatives
-
An efficient copper-catalyzed C-N bond cleavage of aromatic methylamines was developed to construct pyridine derivatives. With neat conditions and facile operation, the fragment-assembling strategy affords a broad range of 2,4,6-trisubstituted pyridines in up to 95% yield from simple and readily available starting materials. Interestingly, when pyridin-2-yl methylamine was employed as the substrate, α-alkylation reaction of ketones readily occurred to give β-(pyridin-2-yl) ketones instead of the 2,4,6-trisubstituted pyridines.
- Huang, Huawen,Ji, Xiaochen,Wu, Wanqing,Huang, Liangbin,Jiang, Huanfeng
-
p. 3774 - 3782
(2013/06/05)
-
- Copper-Catalyzed coupling of oxime acetates with aldehydes: A new strategy for synthesis of pyridines
-
Copper-catalyzed coupling of oxime acetates with aldehydes offers a new strategy for the synthesis of highly substituted pyridines. This novel method tolerates a wide range of functionality and allows for rapid elaboration of the oxime acetates into a variety of substituted pyridines.
- Ren, Zhi-Hui,Zhang, Zhi-Yuan,Yang, Bing-Qin,Wang, Yao-Yu,Guan, Zheng-Hui
-
p. 5394 - 5397
(2011/12/02)
-
- Barium chloride dispersed on silica gel nanoparticles: An efficient catalyst for the preparation of 2,4,6-triarylpyridines under solvent-free conditions
-
BaCl2 dispersed on a nano-structural type of silica gel (BaCl2-nano SiO2) was found to be an effective catalyst for the rapid and high yielding preparation of substituted 2,4,6-triarylpyridine frameworks by the reaction of various aceto-phenones, benzaldehydes and ammonium acetate. The prepared catalyst was characterised by X-ray diffraction and scanning electron microscopy analysis.
- Shafiee, Mohammad Reza Mohammad,Moloudi, Raheleh
-
experimental part
p. 294 - 297
(2011/10/05)
-
- Solvent-free preparation of 2,4,6-triaryl pyridines using silver(I) nitrate adsorbed on silica gel nanoparticles (AgNO3-Nano SiO2) as an efficient catalyst
-
Three-component condensation of substituted acetophenones, aromatic aldehydes, and ammonium acetate catalyzed by silver(I) nitrate adsorbed on silica gel nanoparticles (AgNO3-nano SiO2) has been accomplished for the synthesis of a series of 2,4,6-triaryl pyridines in good to excellent yields under solvent-free conditions.
- Shafiee, Mohammad R.M.,Moloudi, Raheleh
-
experimental part
p. 717 - 721
(2012/06/01)
-
- 2- and 4-(α-Substituted Aryl)pyridines as Leaving Groups in SN2 Reactions and Radicaloid Nucleophilic Displacements.
-
Compared with 2,4,6-triphenylpyridine, 2,6-diphenyl-4-(o-substituted phenyl)pyridines as leaving groups in the radicaloid nucleophilic displacement reaction with 2-nitropropanide anion slow down C.T.C. formation. o-Substitution of the 2-phenyl group has little effect on this reaction.The latter modification however decreases SN2 rates of the corresponding pyridiniums with piperidine.
- Katritzky, Alan R.,Elisseou, E. Michael,Bashiardes, George,Patel, Ranjan C.
-
p. 301 - 320
(2007/10/02)
-