35299-71-9Relevant academic research and scientific papers
Thiophene-based fluorescent mercury-sensors
Shigemoto, Austin K.,Virca, Carolyn N.,Underwood, Samuel J.,Shetterly, Lauren R.,McCormick, Theresa M.
, p. 2081 - 2089 (2016)
Coordination chemistry of thiophene rings is poorly understood, despite their common use in organic electronic materials. The absorption and emission responses to transition metal ions of three thiophene-based ligands containing pyridine chelating groups are examined. These ligands, 2-(2′-thienyl)-pyridine (L1), 2,5-bis(2-pyridyl)thiophene (L2), and 2,6-bis(2-thienyl)pyridine (L3), show a ratiometric fluorescence response in the presence of Hg(ClO4)2 with reasonable selectivity against many transition metal ions in acetonitrile. 1H NMR data support S,N chelation of L1 and L2 to the Hg(II) center, while L3 coordinates through cyclometalation via one carbon of thiophene. DFT calculations suggest thiophene coordinates to Hg(II) in a bent geometry. Our results indicate that thiophene could offer selectivity for Hg(II) towards the design of fluorescent sensors.
Synthesis and Studies of Stable Nonaromatic Dithia Pyribenzihexaphyrins
Rawat, Nisha,Sinha, Avisikta,Prasannan, Dijo,Ravikanth, Mangalampalli
, p. 6665 - 6673 (2021)
We report here one of the rare examples of expanded hexaphyrins named as dithia pyribenzihexaphyrin macrocycles containing six-membered rings such as pyridine and p-phenylene along with five-membered heterocycles such as pyrrole and thiophene as a part of a macrocyclic frame. Trifluoroacetic acid catalyzed [3 + 3] condensation of equimolar mixture of [10,10′-bis(p-tert-butyl phenyl)hydroxymethyl]-1,3-bis(2-thienyl)pyridine diol (2,6-pyri diol) and 1,4-bis(phenyl(1H-pyrrol-2-yl)methyl)benzene (p-benzidipyrrane) in CH2Cl2 followed by oxidation with DDQ afforded stable nonaromatic dithia 2,6-pyri-para-benzihexapyrins 1 and 2 in 6-8% yields. The macrocycles were characterized by high-resolution mass spectroscopy and 1D and 2D NMR spectroscopy. NMR studies revealed the nonaromatic nature of dithia 2,6-pyri-p-benzihexaphyrins and indicated that the para-phenylene ring prefers to be in quininoid form rather than in benzenoid form. The macrocycles displayed sharp absorption bands in the region of ～380-500 nm and a broad band at ～700 nm, reflecting their nonaromatic nature. Upon protonation, these macrocycles showed NIR absorption properties. The redox studies of macrocycles indicated their electron-deficient nature. The DFT/TD-DFT studies are in line with the experimental observations.
In search of oligo(2-thienyl)-substituted pyridine derivatives: A modular approach to di-, tri- and tetra(2-thienyl)pyridines
Bera, Mrinal K.,Hommes, Paul,Reissig, Hans-Ulrich
, p. 11838 - 11843 (2011)
Herein, we describe our attempts to systematically prepare a series of oligo(2-thienyl)-substituted pyridine derivatives. The crucial starting material, a β-alkoxy-β-ketoenamide, is easily available on a large scale by the reaction of lithiated methoxyallene with thiophene-2-carbonitrile and thiophene-2-carboxylic acid. This three-component reaction is followed by intramolecular cyclization to yield the suitably functionalized 2,6-di(2-thienyl)-substituted pyridine derivates. The two oxygen atoms allow the programmed activation of positions C-3, C-4, or C-5 of the pyridine ring to perform palladium-catalyzed coupling reactions with thiophene-2-boronic acid or 2-(tributylstannyl)thiophene, and alternatively, reductive removal of groups. With this concept, we were able to prepare five pyridine derivatives with 2-thienyl substituents in the 2,6-, 2,3,6-, 2,4,6-, 2,3,4,6-, and 2,3,5,6-positions. 2,3,4,5,6-Penta(2-thienyl)pyridine was not available with our methods. The UV/Vis and fluorescence spectra of all pyridines were recorded and showed a dependence on the substitution pattern and protonation state. For the protonated 2,3,5,6-tetra(2-thienyl)-substituted pyridine, a Stokes shift of about 180 nm with an emission at 515 nm was observed.
One-pot synthesis of symmetrical 2,6-diarylpyridines via palladium/copper-catalyzed sequential decarboxylative and direct C-H arylation
Ma, Zhiyong,Liu, Hailong,Zhang, Chunchun,Zheng, Xueli,Yuan, Maolian,Fu, Haiyan,Li, Ruixiang,Chen, Hua
supporting information, p. 1143 - 1148 (2015/04/22)
A palladium(II)/copper oxide (Cu2O)-catalyzed one-pot decarboxylative and direct C-H arylation of 2-picolinic acid with aryl bromides has been developed. Various aryl bromides have been shown to be efficient coupling partners in the presence of dimethyl sulfate, furnishing symmetrical 2,6-diarylpyridines in moderate to good yields.
Ruthenium-catalyzed cyclization of ketoxime acetates with DMF for synthesis of symmetrical pyridines
Zhao, Mi-Na,Hui, Rong-Rong,Ren, Zhi-Hui,Wang, Yao-Yu,Guan, Zheng-Hui
, p. 3082 - 3085 (2014/06/23)
A novel ruthenium-catalyzed cyclization of ketoxime carboxylates with N,N-dimethylformamide (DMF) for the synthesis of tetrasubstituted symmetrical pyridines has been developed. A methyl carbon on DMF performed as a source of a one carbon synthon. And NaHSO3 plays a role in the reaction.
The intramolecular aryl embrace: From light emission to light absorption
Bozic-Weber, Biljana,Constable, Edwin C.,Housecroft, Catherine E.,Kopecky, Peter,Neuburger, Markus,Zampese, Jennifer A.
experimental part, p. 12584 - 12594 (2012/01/06)
6-(1-Methylpyrrol-2-yl)-2,2′-bipyridine, 3, and 6-(selenophene-2-yl)- 2,2′-bipyridine, 4, have been prepared and characterized in solution and by structural determinations. Copper(i) complexes [CuL2][PF 6] in which L is 2,2′-bipyridine substituted in the 6-position by furyl, thienyl, N-methylpyrrolyl, selenopheneyl, methyl or phenyl, (L = 1-6) have been synthesized. The complexes have been characterized by electrospray mass spectrometry, and solution NMR and UV-VIS spectroscopies. The single crystal structures of [Cu(1)2][PF6], [Cu(2) 2][PF6], [Cu(3)2][PF6], [Cu(5) 2][PF6] and [Cu(6)2][PF6] have been determined. In those compounds containing an aromatic substituent attached to the bpy unit, the substituent is twisted with respect to the latter. In [Cu(3)2][PF6] and [Cu(5)2][PF6], this results in intra-cation π-stacking between ligands which is very efficient in [Cu(3)2]+ despite the steric requirements of the N-methyl substituents. Face-to-face stacking between the ligands in the [Cu(2)2]+ ion is achieved by complementary substituent twisting and elongation of one Cu-N bond, but there is no analogous intra-cation π-stacking in [Cu(1)2]+. Ligand exchange reactions between [CuL2][PF6] (L = 1-6) and TiO2-anchored ligands 7-10 (L′ = 2,2′-bipyridine-based ligands with CO 2H or PO(OH)2 anchoring groups) have been applied to produce 24 surface-anchored heteroleptic copper(i) complexes, the formation of which has been evidenced by using MALDI-TOF mass spectrometry and thin layer solid state diffuse reflectance electronic absorption spectroscopy. The efficiencies of the complexes as dyes in DSCs have been measured, and the best efficiencies are observed for [CuLL′] with L′ = 10 which contains phosphonate anchoring groups. The Royal Society of Chemistry.
[Pd(Cl)2(P(NC5H10)(C6H 11)2)2] - A highly effective and extremely versatile palladium-based negishi catalyst that efficiently and reliably operates at low catalyst loadings
Bolliger, Jeanne L.,Frech, Christian M.
experimental part, p. 11072 - 11081 (2010/11/16)
[Pd(Cl)2(P(NC5H10)-(C6H 11)2]2] (1) has been prepared in quantitative yield by reacting commercially available [Pd(cod)(Cl)2] (cod = cyclooctadiene) with readily prepared 1-(dicyclohexylphosphanyl)piperidine in toluene under N2 within a few minutes at room temperature. Complex 1 has proved to be an excellent Negishi catalyst, capable of quantitatively coupling a wide variety of electronically activated, non-activated, deactivated, sterically hindered, heterocyclic, and functionalized aryl bromides with various (also heterocyclic) arylzinc reagents, typically within a few minutes at 100°C in the presence of just 0.01 mol% of catalyst. Aryl bromides containing nitro, nitrile, ether, ester, hydroxy, carbonyl, and carboxyl groups, as well as acetais, lactones, amides, anilines, alkenes, carboxylic acids, acetic acids, and pyridines and pyrimidines, have been successfully used as coupling partners. Furthermore, electronic and steric variations are tolerated in both reaction partners. Experimental observations strongly indicate that a molecular mechanism is operative.
Synthesis of 2,6-diaryl-substituted pyridines and their antitumor activities
Son, Jong-Keun,Zhao, Long-Xuan,Basnet, Arjun,Thapa, Pritam,Karki, Radha,Na, Younghwa,Jahng, Yurngdong,Jeong, Tae Cheon,Jeong, Byeong-Seon,Lee, Chong-Soon,Lee, Eung-Seok
, p. 675 - 682 (2008/09/20)
For the development of novel antitumor agents, we designed and synthesized 2,6-diaryl-substituted pyridine derivatives bearing three aryl groups, which are the bioisosteres of terpyridine, and evaluated their biological activities. Most of the 18 prepared compounds showed moderate cytotoxicity against several human cancer cell lines. From the structure-activity relationships we may conclude that the number of aryl groups employed would be critical for their biological activities.
Synthesis and reactivity of imide-derived bisvinyl phosphates. Reactivity of 2,6-disubstituted 1,4-dihydropyridines
Mousset, Deborah,Gillaizeau, Isabelle,Sabatie, Andrea,Bouyssou, Pascal,Coudert, Gerard
, p. 5993 - 5999 (2007/10/03)
Symmetrical and unsymmetrical 2,6-disubstituted dihydropyridines were prepared in high yields under mild conditions using the Suzuki and Stille Pd-catalyzed coupling reactions of imide-derived bisvinyl phosphates with a range of aryl, heteroaryl, and alkenyl moieties. The alkylation reaction at C-4 easily afforded original tri- and tetrasubstituted dihydropyridines. Hydrolysis of the latter under acidic condition provided efficiently either open-chain 1,5-diketones or di- or trisubstituted pyridines.
Pyridine ring formation through the photoreaction of arenecarbothioamides with diene-conjugated carbonyl compounds
Oda, Kazuaki,Nakagami, Rikiji,Nishizono, Naozumi,Machida, Minoru
, p. 2371 - 2372 (2007/10/03)
Irradiation of arenecarbothioamides with hexa-2,4-dienal in benzene solution gives 2-arylpyridines in moderate yields.
