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1.
A novel and simple synthetic route for the preparation of a series of functionalized mixed thiophene/furan oligomers is described. This method, involving a Mn(OAc)3‐mediated oxidative addition of β‐thienyl‐β‐keto esters (=β‐oxothiophenepropanoates) to methyl 3‐thienylprop‐2‐enoates, allows the construction of highly functionalized heteropolyaromatic oligomers possessing various chain lengths (Schemes 2, 4, and 5). Moreover, the straightforward transformation of the carbonyl functions appended to the furan rings leads to polycarboxylic acid precursors of H2O‐soluble conducting polymers (Scheme 6). 相似文献
2.
π‐Conjugated oligomers and polymers consisting of bifuran units are applied in optoelectronic devices, because bifuran units endow such devices with superior properties compared with their thiophene analogs. However, as is true for most furan oligomers, bifuran oligomers suffer from low photostability, which restricts their application. In this work, we present the synthesis and the photophysical and structural characterization of perfluorinated phenyl bifuran ( PFB‐2F ), which displays high photostability, while maintaining strong fluorescence quantum efficiency in both solution and the solid state. X‐Ray crystallography reveals that, unlike its thiophene analog, PFB‐2F has a completely planar backbone, with slip‐stacked packing and short interplanar distances. PFB‐2F crystals display mechanofluorochromic behavior, which renders perfluorophenyl‐substituted oligofurans potential candidates for both stable optoelectronic devices and responsive optical materials. 相似文献
3.
Palas Baran Pati Soumyajit Das Sanjio S. Zade 《Journal of polymer science. Part A, Polymer chemistry》2012,50(19):3996-4003
Four D–A–D type co‐oligomers have been synthesized by Stille condensation between monostannyl derivatives of furan/thiophene/selenophene/3,4‐ethylenedioxythiophene (EDOT) and 4,7‐dibromo‐benzo[1,2,5]oxadiazole. All these co‐oligomers were successfully electrochemically polymerized in dichloromethane and characterized by spectroelectrochemistry. All four polymers possess narrow optical band gap. Spectroelectrochemical studies of polymer films on indium tin oxide revealed that the replacement of donor EDOT with furan/thiophene/selenophene has affected the low‐energy charge‐carrier (bipolaron) formation significantly. Kinetic studies based on chronoamperometry show that the polymer P5 (EDOT‐capped benzo[1,2,5]oxadiazole system) possess better electrochromic property with high transmittance (66%) in visible region than the other copolymers. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
4.
Tiit Jüuurimaue Marek Strandberg Mati Karelson Jean-Louis Calais 《International journal of quantum chemistry》1995,54(6):369-379
Four common five-membered heterocycles—pyrrole, phosphole, thiophene, and furan—and their oligomers with the chain length of 2, 4, 6, and 10 units have been studied quantum chemically using the semiempirical PM 3 parameterization. The oligomers of pyrrole and phosphole with the homolytically dissociated N? H bond and P? H bond, respectively, and oligomers of thiophene and furan with one electron removed per monomer unit (4n + 2 π-electron bipolaron systems) have also been studied. The electronic properties of the respective polymers were extrapolated from the oligomer data. Bulk polymer effects on the electronic structure were modeled using the self-consistent reaction field theory in the multicavity approximation (MC a SCRF ). © 1995 John Wiley & Sons, Inc. 相似文献
5.
Carlos Alemn 《Macromolecular theory and simulations》1997,6(1):237-245
The molecular geometries of neutral and dicationic oligomers comprising 7, 10, 13 and 16 rings of thiophene, furan and pyrrole were determined using quantum mechanical calculations. The usual benzenoid structure was characterized for neutral oligomers, whereas a quinoid structural defect which extends over six rings was found for dications. Analysis of the transition region, where the quinoid structure changes to the benzenoid one, revealed structural differences between thiophene, furan and pyrrole derivatives. 相似文献
6.
Yasuo Miyata Dr. Miki Terayama Takeo Minari Dr. Tohru Nishinaga Dr. Takashi Nemoto Dr. Seiji Isoda Prof. Koichi Komatsu Prof. 《化学:亚洲杂志》2007,2(12):1492-1504
Oligo(thienylfuran)s with thiophene rings at both ends ( SOSOSOS , DE‐SOSOS , DH‐SOSOS , DE‐SOSOSOS , and DH‐SOSOSOS ; S and O denote thiophene and furan rings, respectively, DE and DH denote diethyl‐ and dihexyl‐substituted, respectively) were newly synthesized by repetitive Stille coupling reactions. The UV/Vis maximum absorptions of the oligomers, SO , SOSO , SOSOS , SOSOSO , and SOSOSOS , exhibited a clear bathochromic shift with increasing number of heterocycles. The value of the oxidation peak potential (Epa1) determined by cyclic voltammetry decreased with an increase in the number of heterocycles by 0.06–0.08 V per heterocycle. The crystal‐packing structures of DE‐SOSOS and DH‐SOSOS determined by X‐ray crystallography have a herringbone motif and are denser than the reported structures of pentacene and α‐sexithiophene. The morphologies of thin films prepared by vacuum deposition and spin coating were investigated by atomic force microscopy and X‐ray diffraction. Among these films, those of DE‐SOSOS and DH‐SOSOS exhibited highly ordered arrangements. The devices based on vacuum‐deposited and spin‐coated films of DE‐SOSOS and DH‐SOSOS displayed the highest FET mobilities of 10?2–10?3 cm2 V?1 s?1 among the oligomers reported in this study. 相似文献
7.
Prof. Yanli Zeng Dr. Xueying Zhang Dr. Xiaoyan Li Prof. Lingpeng Meng Prof. Shijun Zheng 《Chemphyschem》2011,12(6):1080-1087
The halogen bonding of furan???XY and thiophene???XY (X=Cl, Br; Y=F, Cl, Br), involving σ‐ and π‐type interactions, was studied by using MP2 calculations and quantum theory of “atoms in molecules” (QTAIM) studies. The negative electrostatic potentials of furan and thiophene, as well as the most positive electrostatic potential (VS,max) on the surface of the interacting X atom determined the geometries of the complexes. Linear relationships were found between interaction energy and VS,max of the X atom, indicating that electrostatic interactions play an important role in these halogen‐bonding interactions. The halogen‐bonding interactions in furan???XY and thiophene???XY are weak, “closed‐shell” noncovalent interactions. The linear relationship of topological properties, energy properties, and the integration of interatomic surfaces versus VS,max of atom X demonstrate the importance of the positive σ hole, as reflected by the computed VS,max of atom X, in determining the topological properties of the halogen bonds. 相似文献
8.
Reaction between Furan‐ or Thiophene‐2‐carbonyl Chloride,Isocyanides, and Dialkyl Acetylenedicarboxylates: Multicomponent Synthesis of 2,2′‐Bifurans and 2‐(Thiophen‐2‐yl)furans
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Mohammad Hosein Sayahi Mehdi Adib Zeinab Hamooleh Long‐Guan Zhu Massoud Amanlou 《Helvetica chimica acta》2015,98(9):1231-1239
An efficient multi‐component synthesis of highly functionalized 2,2′‐bifurans and 2‐(thiophen‐2‐yl)furans is described. A mixture of furan‐ or thiophene‐2‐carbonyl chloride, an isocyanide, and a dialkyl acetylenedicarboxylate undergoes a smooth addition reaction in dry CH2Cl2 at ambient temperature to produce 2‐amino‐5‐(4‐chlorofuran‐2‐yl)furan‐3,4‐dicarboxylates and 2‐amino‐5‐(4‐chlorothiophen‐2‐yl)furan‐3,4‐dicarboxylates. A single‐crystal X‐ray‐analysis of a derivative conclusively confirms the structure of these 2,2′‐bifurans and 2‐(thiophen‐2‐yl)furans. A novel electrophilic aromatic substitution reaction can justify the formation of the Cl‐substituted furan or thiophene rings. 相似文献
9.
A coordinatively unsaturated iron‐methyl complex having an N‐heterocyclic carbene ligand, [Cp*Fe(LMe)Me] ( 1 ; Cp*=η5‐C5Me5, LMe=1,3,4,5‐tetramethyl‐imidazol‐2‐ylidene), is synthesized from the reaction of [Cp*Fe(TMEDA)Cl] (TMEDA=N,N,N′,N′‐tetramethylethylenediamine) with methyllithium and LMe. Complex 1 is found to activate the C? H bonds of furan, thiophene, and benzene, giving rise to aryl complexes, [Cp*Fe(LMe)(aryl)] (aryl=2‐furyl ( 2 ), 2‐thienyl ( 3 ), phenyl ( 4 )). The C? H bond cleavage reactions are applied to the dehydrogenative coupling of furans or thiophenes with pinacolborane (HBpin) in the presence of tert‐butylethylene and a catalytic amount of 1 (10 mol % to HBpin). The borylation of the furan/thiophene or 2‐substituted furans/thiophenes occurs exclusively at the 2‐ or 5‐positions, respectively, whereas that of 3‐substituted furans/thiophenes takes place mainly at the 5‐position and gives a mixture of regioisomers. Treatment of 2 with 2 equiv of HBpin results in the quantitative formation of 2‐boryl‐furan and the borohydride complex [Cp*Fe(LMe)(H2Bpin)] ( 5 ). Heating a solution of 5 in the presence of tert‐butylethylene led to the formation of an alkyl complex [Cp*Fe(LMe)CH2CH2tBu] ( 6 ), which was found to cleave the C? H bond of furan to produce 2 . On the basis of these results, a possible catalytic cycle is proposed. 相似文献
10.
A butyl methacrylate oligomer with furan end-groups was synthesized by ozonolysing a poly(butyl methacrylate-co-butadiene) latex. The end-groups of this oligomer were amidated with aminomethylfuran to give a coagulated mass of derivatized oligomers. This furan functional oligomer was then mixed with poly(ethylene oxide-co-acetylenedicarboxylate) and heated at 60°C or 125°C. The material cured at 125°C was found to contain a higher gel fraction (55 wt.-%) than that cured at 60°C (30 wt.-%). 相似文献
11.
Naime Akbaşoğlu Abidin Balan Derya Baran Ali Cirpan Levent Toppare 《Journal of polymer science. Part A, Polymer chemistry》2010,48(23):5603-5610
Two new 2‐dodecyl benzotriazole (BTz) based donor‐acceptor‐donor (DAD) type polymers were synthesized and characterized in terms of their electrochemical and spectral properties. These DAD type polymers were synthesized electrochemically from furan or thieno[3,2‐b]thiophene (TT) end‐capped BTz monomers. Furan based and thieno[3,2‐b]thiophene based monomers showed monomer oxidations at 1.15 and 1.25 V, respectively, which eased the formation of conducting polymer films without overoxidation. Cyclic voltammetry and spectroelectrochemistry studies showed that both materials are multicolored electrochromic polymers. Results and comparison with properties of other BTz based DAD type polymers are highlighted in detail. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
12.
Sultana Ferdous Jolanta B. Lagowski 《Journal of Polymer Science.Polymer Physics》2007,45(15):1983-1995
Ab Initio study of the ground and excited state polarizabilities of thiophene, fulvene, and cyclopentadiene based conducting oligomers and their cyano derivatives have been performed using the restricted Hartree–Fock (RHF) and the configuration interaction singles (CIS) approaches, respectively, with 3‐21G* basis set. For comparison purposes, for some small oligomers (monomers and dimers), higher basis sets (6‐31G*, 6‐31+G*, aug‐cc‐pVTZ) were also employed in the computations of polarizabilities. The trends in polarizability as a function of oligomer length were investigated. For all systems, the RHF polarizability increases as n1.2–1.3 as n gets larger and the CIS polarizability increases as n1.4–1.6 for n less than seven or eight rings and then increases approximately linearly with n for larger n. For the thiophene based systems the dependence of the polarizability on bond length alternation (BLA) along the backbone of the oligomers was also investigated using the RHF, density functional (DFT), and CIS theories (with 3‐21G* basis set). For thiophene dimer, we also performed RHF/aug‐cc‐pVTZ calculations of polarizabilities versus BLA. We found that the polarizability is largest when BLA is near zero (for both ground and excited states), which correlates with the lowest excitation energy. Comparison with experimental results has been made where possible. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1983–1995, 2007 相似文献
13.
Direct Arylation of 5‐Iodouracil and 5‐Iodouridine with Heteroarenes and Benzene via Photochemical Reaction
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A method for the direct arylation of 5‐iodouracil and 5‐iodouridine was found to proceed in moderate yields. By irradiating mixtures of 5‐iodouracil or 5‐iodouridine and a series of five‐membered heterocycles such as 1H‐pyrrole, furan, 2‐methylfuran, 1‐methyl‐1H‐pyrrole, thiophene, as well as benzene in MeCN/H2O with a Hg lamp, 5‐aryluracils and 5‐aryluridines were synthesized. The reaction proceeded smoothly without the requirement of adding any transition metals or ligands. 相似文献
14.
A Gold‐Catalyzed Domino Cyclization Enabling Rapid Construction of Diverse Polyheterocyclic Frameworks
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Yi He Dr. Zhenghua Li Dr. Koen Robeyns Prof. Dr. Luc Van Meervelt Prof. Dr. Erik V. Van der Eycken 《Angewandte Chemie (International ed. in English)》2018,57(1):272-276
We report herein an efficient gold(I)‐catalyzed post‐Ugi domino dearomatization/ipso‐cyclization/Michael sequence that enables access to libraries of diverse (hetero)arene‐annulated tricyclic heterocycles. This process affords novel complex polycyclic scaffolds in moderate to good yields from readily available acyclic precursors with excellent chemo‐, regio‐, and diastereoselectivity. The power of this strategy has been demonstrated by the rapid synthesis of 40 highly functionalized polyheterocycles bearing indole, pyrrole, (benzo)furan, (benzo)thiophene, pyrazole, and electron‐rich arene groups in two operational steps. 相似文献
15.
Systematic NMR characterization of 4‐thio‐5‐furan‐pyrimidine nucleosides or 4‐thio‐5‐thiophene‐pyrimidine nucleosides (ribonucleosides and 2′‐deoxynucleosides) was performed. All proton and carbon signals of 4‐thio‐5‐thiophene‐ribouridine and related analogues were unambiguously assigned. The orientations of the base (4‐thiouridine or its deoxy analogue) relative to the ring (furan or thiophene) are explored by a NMR approach and further supported by X‐ray crystallographic studies. The procedures presented here would be applicable to other modified nucleosides and nucleotides. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
16.
Efficient Synthetic Approach to Substituted Benzo[b]furans and Benzo[b]thiophenes by Iodine‐Promoted Cyclization of Enaminones
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Ehecatl Labarrios Alberto Jerezano Fabiola Jiménez María del Carmen Cruz Francisco Delgado L. Gerardo Zepeda Joaquín Tamariz 《Journal of heterocyclic chemistry》2014,51(4):954-971
An efficient synthetic approach to the substituted benzo[b]furan and benzo[b]thiophene scaffolds by iodine‐mediated cyclization of the corresponding enaminones is described. This protocol was applied to a large series of these latter precursors to afford the respective benzoheterocycles substituted at the C‐2 position by a carbonyl group functionality. A study of the factors that control this process reveals that the reactivity depends on the presence of electron‐donor groups in the aryl ring of the aryloxycarbonylic and arylthiocarbonylic moieties. 相似文献
17.
David E. Bergbreiter Martha L. Liu 《Journal of polymer science. Part A, Polymer chemistry》2001,39(23):4119-4128
Interphase oligomerization of thiophene within a supported thin film is described. Polyethylene (PE) surfaces containing an irregularly hyperbranched poly(acrylic acid) (PAA) graft were first prepared by multistep grafting of poly(tert‐butylacrylate) onto oxidized PE. The product ultrathin PAA grafts were then further modified by amidation or esterification with thiophenes containing amino or hydroxyl groups to form new interfaces containing thiophene monomers. These thiophene‐modified grafts were characterized by attenuated total reflectance infrared spectroscopy and were shown to be suitable as substrates in an oxidative polymerization method with FeCl3 as an oxidant. The product 2,5‐coupled thiophene oligomers (3‐PAA/PE–oligomerized thiophene ester, OTE) emitted a yellow‐green light under UV irradiation, indicating that a conjugated fluorescence oligothiophene had been prepared within these hyperbranched films. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4119–4128, 2001 相似文献
18.
Alan R. Katritzky Zhongxing Zhang Hengyuan Lang Nusrallah Jubran Louis M. Leichter Norman Sweeny 《Journal of heterocyclic chemistry》1997,34(2):561-565
2-Mono- and 2,5-bis[bis[(4-dimethylamino)phenyl]hydroxymethyl]substituted furan, thiophene and N-methylpyrrole were synthesized by mono- and dilithiation of furan, thiophene and N-methylpyrrole, respectively, and subsequent reaction with Michler's ketone. The title compounds develop black or dark-blue colors in acidic media. 相似文献
19.
Computer simulation of the lanthanide induced shifts has been applied to study of the conformational preferences in the 2-formyl and 2-acetyl derivatives of furan, thiophene, selenophene and tellurophene. The results assign a nearly equipopulated mixture of s-cis and s-trans conformers to the furan, and a preponderance of the s-trans form to the thiophene, selenophene and tellurophene derivatives. This difference is interpreted as due to the interaction between the heteroatom and carbonyl oxygen lone pairs. The 2-N,N-dimethylcarboxyamide derivatives of furan, thiophene and selenophene are found to exist mainly in a quasi-planar s-cis form. The barriers to the rotation about the amide bond in these amides have been measured and related to the electronegativity of the heteroatom. 相似文献
20.
Systematic investigation of asymmetric trimethylsilylcyanation of heterocyclic azomethines has been realized. The addition of trimethylsilyl cyanide to optically active furan, thiophene and pyridine aldimines, derived from (R)‐ and (S)‐1‐phenylethylamine, was studied in the presence of Lewis acids, and a series of the corresponding α‐amino nitriles was obtained in fair to good yields (up to 91%). Unsaturated nitriles were also formed from pyridine imines. The sense of asymmetric induction and the degree of diastereoselectivity in the synthesis of α‐amino nitriles were determined by means of 1H NMR. The stereochemical outcome is a result of the same sense of asymmetric induction: Re face attack to the (S)‐imines and Si face addition to the (R)‐imines took place. The (R,R)‐ (up to 81%) or (S,S)‐ (up to 87%) α‐amino nitriles predominated in the products obtained from the all furan, thiophene and pyridine (R)‐ or (S)‐imines respectively. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献