50553-98-5Relevant articles and documents
Sulfonated poly(ether sulfone)s containing pyridine moiety for PEMFC
Jang, Hohyoun,Islam, Md. Monirul,Lim, Youngdon,Hossain, Md. Awlad,Cho, Younggil,Joo, Hyunho,Kim, Whangi,Jeon, Heung-Seok
, p. 7798 - 7803 (2014)
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.
Synthesis of Kr?hnke pyridines through iron-catalyzed oxidative condensation/double alkynylation/amination cascade strategy
Gopalaiah, Kovuru,Choudhary, Renu
supporting information, (2021/09/15)
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.
Copper-catalyzed efficient access to 2,4,6-triphenyl pyridinesviaoxidative decarboxylative coupling of aryl acetic acids with oxime acetates
Bharat Kumar, Karasala,Chinnari, Lekkala,Shyamala, Pulipaka,Siddaiah, Vidavalur,Varaprasad, Bodala
supporting information, p. 15205 - 15209 (2021/09/06)
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
An efficient one pot three-component synthesis of 2,4,6-triarylpyridines using triflimide as a metal-free catalyst under solvent-free conditions
Wang, Hongshe,Zhao, Weixing,Du, Juan,Wei, Fenyan,Chen, Qi,Wang, Xiaomei
, p. 5158 - 5163 (2019/02/27)
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.