Thiophene

11 Key excerpts on "Thiophene"

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  eBook - ePub

  Progress in Heterocyclic Chemistry

  • Gordon Gribble, J. Joule, Gordon W. Gribble(Authors)
  • 2009(Publication Date)
  • Elsevier

    (Publisher)

  Chapter 5.1: Five-Membered Ring Systems: Thiophenes and Se/Te Analogues

  Tomasz Janosik (email: [email protected] ) and Jan Bergman (email: [email protected] )

  Department of Biosciences and Nutrition, Karolinska Institute, Novum Research Park, SE-141 57

  Huddinge, Sweden

  5.1.1. Introduction

  The strong and continuously increasing interest in Thiophene chemistry is manifested in a multitude of new publications that appeared during the year 2008, where this important heterocycle is represented in research fields such as materials science and medicinal chemistry. Such diverse applications of Thiophene derivatives have in turn inspired further studies in Thiophene ring synthesis, as well as new developments in modifications of existing Thiophene compounds.

  As in previous years, there are several new reviews available. Although some of these accounts target topics associated with Thiophene-based materials, such as layers of oligoThiophenes in nanoscale electronic devices < 08ACR1098 >, polyThiophene semiconductors for transistor applications < 08CEJ4766 >, annulated oligoThiophenes < 08MC171 >, photochromic Thiophene-containing materials < 08BCJ917 >, and the use of palladium-catalyzed CH arylation and homocoupling in construction of organic materials < 08BCJ548 >, a series of chapters in the most recent edition of Comprehensive Heterocyclic Chemistry are devoted to more fundamental aspects, namely structure < 08CHC(III)625 >, reactivity < 08CHC(III)741 >, ring synthesis < 08CHC(III)843 >, as well as applications < 08CHC(III)931 >. A general review covering the development of organic semiconductors for solution-processable field-effect transistors has also been published, providing numerous references to Thiophene-based studies < 08AG(E)4070 >. Finally, a contribution detailing the advances in synthesis of fused Thiophenes by the aromatic ortho-Claisen rearrangement has also become available < 08SL2400

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  Progress in Heterocyclic Chemistry

  A Critical Review of the 2000 Literature Preceded by Two Chapters on Current Heterocyclic Topics

  • G.W. Gribble, Thomas L. Gilchrist(Authors)
  • 2001(Publication Date)
  • Pergamon

    (Publisher)

  Chapter 5.1

  Five-Membered Ring Systems: Thiophenes & Se, Te Analogs

  Erin T. Pelkey [email protected]     Stanford University, Stanford, CA, USA

  5.1.1 INTRODUCTION

  Reports detailing the chemistry and syntheses of Thiophenes, benzo[b ]Thiophenes, and related ring systems that have appeared during the past year (Jan-Dee 2000) are the primary focus of this review. Different aspects of chemistry that involve Thiophenes have been reviewed during the past year <00AM481 , 00BCSJ1 , 00CR2537 , 00CSR109 , 00PAC1645 >.

  5.1.2 Thiophene RING SYNTHESIS

  One general strategy for preparing the Thiophene ring system is to add sulfur to activated four carbon units. For example, treatment of the zirconocene-based oligomer 1 with sulfur chloride gave the Thiophene-based oligomer 2 by replacement of the zirconium moieties with sulfur <00AC2870 >. The synthesis of a thieno[3,4-c ]Thiophene involved the addition of sulfuryl chloride to a 3,4-dicyanomethylThiophene <00TL8843 >. The central Thiophene ring of the structurally interesting thiahelicene 4 was prepared by dilithiation of 3 with LDA followed by double displacement of bis(phenylsulfonyl) sulfide <00AC4481 >. Additional examples of Thiophene ring synthesis involving the treatment of 1,4-dicarbonyl compounds with Lawesson’s reagent appeared including a synthesis of a terThiophene <00JMAT107 >and a novel fluorophore <00CC939 >.

  One of the most common strategies for the preparation of Thiophenes involves the intramolecular condensation of α-thioglycolates (and related α-substituted thiols) onto adjacent carbonyls. One prominent example involved the synthesis of naturally occurring anthraThiophene pigment 7 <00OL2351 >. A novel addition-elimination of tosylate 5 with methyl thioglycolate gave 6 , which was treated with sodium methoxide to effect an intramolecular cyclization giving 7. This synthesis helped ensure that the correct structure 7 had been assigned to the natuaral product. The preparation of the peri-substituted thieno[2,3-b ]Thiophene 10 was also achieved using this type of condensation with diester 9 <00SC1695 >. The latter was prepared by treating 8 with carbon disulfide and ethyl bromoacetate. Related reaction sequences have been utilized to prepare a variety of Thiophenes including benzo[b ]Thiophene-2-carboxylates <00TL4973 , 00TL5415 >, a 2-acetylbenzo[b ]Thiophene <00H(53)1175 >, 2-trifluoromethyl-Thiophenes <00S1078 >, and benzothiazole-substituted Thiophenes <00HC94 >. A related cyclization reaction of thioacetamides with activated bromides was used to prepare cyanovinyl-substituted Thiophenes <00EJOC1327 >, Thiophene-a-carboxylates, <00EJOC3273 >and a-amine-substituted Thiophenes <00JCS(P1)4316

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  Progress in Heterocyclic Chemistry

  • Gordon Gribble, John A. Joule, Gordon W. Gribble(Authors)
  • 2012(Publication Date)
  • Elsevier

    (Publisher)

  b ]Thiophenes with important drug activities or for use as valuable precursors in drug synthesis. Additionally, the proper design and synthesis of Thiophenes for polymeric, electronic, superconducting, and nonlinear optical materials continued unabated this year. Due to space limitations, we will focus primarily on the synthetic aspects of Thiophene and Se/Te chemistry. Reports with a common flavor have been grouped together wherever possible.

  5.1.2 Reviews, Accounts, and Books on Thiophene, Selenophene, and Tellurophene Chemistry

  The synthesis, properties, and biological activity of Thiophenes <11DPC38> and new developments of synthesis and reactivity of seleno- and tellurophenes have been reviewed <11OBC1301> . Reviews of the chalcogens in material sciences in 2011 include (1) how structural deviations on the backbone of conjugated polymers including poly(p -phenylenevinylene), poly(3-alkyl)Thiophenes, and poly(3-hexyl)selenophene derivatives, thieno[3,2-b ]- and thieno[3,4-b ]Thiophene-based polymers; (2) how bridge biThiophenes with 5-member fused aromatic rings in the central core influence their optoelectronic properties and photovoltaic performance <11PPS1328> ; (3) studies on long-conjugated polymers, that is, oligoThiophenes and oligoselenophenes <11ACR14> ; and (4) will polytellurophenes bridge the gap between conjugated polymers and inorganic solid-state semiconductors? <11MRC943> .

  5.1.3 Synthesis of Thiophenes

  5.1.3.1 Thiophene Rings

  Electrophilic cyclization of alkynes possessing tethered heteroatom nucleophiles and various catalytic reagents has been involved in several strategies for the synthesis of simple and complex heterocycles. Many of these strategies involve the use of palladium as metal catalyst. Recently, copper salts have been used as alternatives to palladium catalyst due to their low cost and lower toxicity. An important synthetic feature is introduced when bromine or iodine is used as electrophilic reagents since the halogen atom introduced into the heterocyclic ring can undergo a wide variety of metal-catalyzed cross-coupling reactions.

  Prior to this year, this methodology has been applied mainly to the synthesis of nitrogen or oxygen five-membered heterocycles. Recently, Zeni et al. have prepared a series of 3-halochalcogenophene derivatives 2 by a copper(II)-mediated intramolecular cyclization of (Z )-chalcogenoenynes 1 . Shown in Scheme 1 is the synthesis of 3-haloThiophenenes <11EJO6713> . To demonstrate the versatility of this reaction, 5-diphenyl-3-bromoselenphene 2a

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  Progress in Heterocyclic Chemistry

  • (Author)
  • 2013(Publication Date)
  • Elsevier

    (Publisher)

  b ]Thiophenes possessing important drug activities or for use as valuable precursors in drug synthesis. Additionally, the proper design and synthesis of Thiophenes for polymeric, electronic, superconducting, and nonlinear optical materials continued unabated this year. Due to space limitations, we will focus primarily on the synthetic aspects of Thiophene and Se/Te chemistry. Reports with a common flavor have been grouped together wherever possible.

  4.1.2 Reviews and Books on Thiophene, Selenophene, and Tellurophene Chemistry

  Several interesting reviews have appeared this year on titled compounds. These include the synthesis, structures, and catalytic activities of several sulfur-functionalized N -heterocyclic carbine complexes of Pd(II) 〈12MOL2491〉 ; synthetic routes to chiral nonracemic and racemic dihydro- and tetrahydroThiophenes 〈12CRV2129〉 ; synthesis and applications of 2,2″6′,C ′-tetrapyridines functionalized with thienyl substituents 〈12JHC453〉 ; chemistry of acyl tropic intramolecular rearrangements of keto enamines of benzo[b ]-annelated Thiophenes, selenophenes, and tellurophenes 〈12CHE107〉 and positional selectivity in electrocyclic substitution reactions of π-excessive heterocycles were reviewed; selenophenes and tellurophenes 〈12CHE241〉 ; and synthesis of thieno[3,4-b ]pyrazines and its extended analogs from 3,4-diaminoThiophene as important building blocks for the production of conjugated materials 〈12JHC479〉 . Several books or book chapters on these chalcogens were published this year. With respect to the former, a chapter on recent advances in Thiophenes ad benzoThiophenes chemistry was published in Topics in Heterocyclic Chemistry 〈12THC347〉 . Also, a chapter on titled compounds appeared in Progress in Heterocyclic Chemistry 〈12PHC139〉 .

  4.1.3 Synthesis of Thiophenes, Selenophenes, and Tellurophenes

  Electrophilic cyclization of alkynes possessing tethered heteroatom nucleophiles using various catalytic reagents continues to be an important strategy for the synthesis of simple and complex heterocycles. For example, as shown below, the facile synthesis of anthra[2,3-b ]Thiophene and anthra[2,3-b ]selenophene was achieved in which the key steps involved electrophilic intramolecular cyclization of 2-bromo-3-alkynylanthracene in the presence of Na2 ·9HOH sodium selenide, respectively 〈12S2102〉

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  Progress in Heterocyclic Chemistry

  • Gordon Gribble, J. Joule, Gordon W. Gribble(Authors)
  • 2005(Publication Date)
  • Elsevier Science

    (Publisher)

  Chapter 5.1

  Five-membered ring systems: Thiophenes and Se/Te analogues

  Tomasz Janosik [email protected] ; Jan Bergman [email protected]     Department of Biosciences at Novum, Karolinska Institute, Novum Research Park, SE-141 57 Huddinge, Sweden, and Södertörn University College, SE-141 04 Huddinge, Sweden

  5.1.1 INTRODUCTION

  This chapter aims at summarizing the developments in Thiophene chemistry, including some aspects on selenophenes and tellurophenes, reported during the period of January to December 2004. The emphasis is put on the synthesis and reactivity of basic Thiophene systems. Much new chemistry in this area is currently focussing on Thiophene containing oligomeric or polymeric organic materials. Even though coverage of these developments are beyond the scope of this chapter, there are short sections devoted to these types of structures included, as well as to the applications of Thiophenes in medicinal chemistry.

  Several specialized reviews on Thiophene containing compounds have appeared during the year. An account on single-crystalline photochromism of thienyl- or benzo[b ]thienyl containing ethenes has been published <04BCJ195 >, while the synthesis, properties and applications of bis(ethylenethio)tetrathiafulvalenes have been reviewed in detail <04CR5289 >. Thiophene- and selenophene-based materials have also been included in a review on the recent progress in semiconductor performance of devices based on such ring systems <04CM4748 >. An account on the role of single-site catalysts in the hydrodesulfurization of Thiophenes has been provided <04JOM(689)4277 >. Fused Thiophene systems, for example thienopyridazines <04PS321 >, and thienopyrimidines <04RCB487 > have also been covered. A review concerning the chemistry and properties of benzo[b ]tellurophene, dibenzo[b ,d ]tellurophene and their derivatives has appeared <04CHE834 >. Various aspects on the aromaticity of Thiophene and its Se and Te analogs have been discussed in an account on the aromaticity of heterocyclic compounds in general <04CR2777 >. Finally, an excellent monograph detailing the best synthetic methods in Thiophene chemistry has become available <04MI1

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  Thiophene and Its Derivatives, Volume 44, Part 2

  • Salo Gronowitz(Author)
  • 2009(Publication Date)
  • Wiley-Interscience

    (Publisher)

  it is first necessary to consider some basic facts about the molecule . Like all the five-membered heterocycles. Thiophene is classed as e1ectron.rich. there being six 77 electrons delocalized over five atoms . The occurrence of delocali- Introduction 3 zation is confirmed by the structure of the molecule (elucidated from the micro- wave ~pectrum)~ given in 1. This shows that the C-S, C-C, and C=C bonds are respectively shorter, longer, and shorter than they would be in an isolated state, when values of ca. 1.82, 1.54, and 1.38 a would apply. Given that delocalization occurs, then the ring must have a higher 77 density than in benzene, and the greater ease of electrophilic substitution follows. 1.4232 a 1 1227' l~28~m 1.3996 a 92010' S 1.714 A 1 Prediction of the reactivity relative to other five-membered heterocycles is less easy. A priori it might seem that the less aromatic the heterocycle, the less stable it will be and the greater the ease of electrophilic substitution, but this turns out to be only approximately true. There are three principal measures available for assessing the aromaticity of these compounds: 1. Resonance energies,536 which give the aromaticity order: benzene >> Thiophene 2 pyrrole > selenophene > tellurophene > furan. 2 . NMR ring currents7, which predict the order: Thiophene > pyrrole > furan (al- though this conclusion is disputed'). 3. The bond length ratios C2-C3/C3-C4 (one cannot use the X-C2 bond lengths because these are very dependent upon the size of the heteroatom X). They also predict the order: (benzene) > Thiophene > pyrrole > selenophene > f ~ r a n . ~ ~ ~ In addition, bond-electron gradients give the order: Thiophene - pyrrole > furan, while molar magnetic rotations and magnetic moment susceptibilities both give the order: Thiophene > pyrrole > furan. Thus although all the five-membered heterocycles are correctly predicted to be much more reactive than benzene, the reactivity order within the heterocyclic series is wrong.

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  Thiophene and Its Derivatives, Volume 44, Part 5

  • Salo Gronowitz(Author)
  • 2009(Publication Date)
  • Wiley-Interscience

    (Publisher)

  Thiophene AND ITS DERIVATIVES Part Five Edited by Salo Gronowitz University of Lund Lund. Sweden AN INTERSCIENCE PUBLICATION JOHN WILEY AND SONS NEW YORK 0 CHICHESTER 0 BRISBANE a TORONTO 0 SINGAPORE In recognition of the importance of preserving what has been written, it is a policy of John Wiley & Sons, Inc., to have books of enduring value published in the United States printed on acid-free paper, and we exert our best efforts to that end. Copyright All rights reserved. Published simultaneously in Canada. Reproduction of translation of any part of this work beyond that permitted by Section 107 or 108 of the 1976 United States Copyright Act without the permission of the copyright owner is unlawful. Requests for permission or further information should be addressed to the Permissions Department, John Wiley & Sons, Inc. Library of Congress Cataloging in Publication Data: (Revised for vol. 5) Thiophene and its derivatives 1992 by John Wiley & Sons, Inc. (The Chemistry of heterocyclic compounds, 0069-3154 v. 44) “An Interscience publication.” Includes bibliographies and indexes. 1. Thiophene. I. Gronowitz, Salo. 11. Series. QD403.T55 1985 547‘.594 84-15356 ISBN 0-471-38120-9 (v. 1) ISBN 0-471-52944-3 (v. 5) Contributors Torbjorn Frejd, Division of Organic Chemistry 2, Chemical Center, University of Lund, Lund, Sweden Salo Cronowitz, Division of Organic Chemistry 1, Chemical Center, University of Lund, Lund, Sweden Rolf Hiikansson, University College of Kalmar, Kalmar, Sweden Anna-Britta Hornfeldt, Division of Organic Chemistry 1, Chemical Center, University of Lund, Lund, Sweden V This Page Intentionally Left Blank The Chemistry of Heterocyclic Compounds Introduction to the Series The chemistry of heterocyclic compounds constitutes one of the broadest and most complex branches of chemistry.

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  Metal-Free Synthetic Organic Dyes

  • Ghodsi Mohammadi Ziarani, Razieh Moradi, Negar Lashgari, Hendrik G. Kruger(Authors)
  • 2018(Publication Date)
  • Elsevier

    (Publisher)

  Chapter 16

  Thiophene Dyes

  Abstract

  Thiophene is a heterocyclic compound consisting of a planar five-membered ring that improves the photovoltaic performance of dye-sensitized solar cells (DSSCs) (Hara et al., 2005; Dentani et al., 2009; Zhang et al., 2009; Kim et al., 2012; Naka et al., 2016; Imae et al., 2015) [1–6]. Recently a series of efficient DSSCs were reported using new sensitizers containing Thiophene unit as the spacer (Thomas et al., 2005) [7]. Thiophene-based π-conjugated oligomers and polymers have been widely used in photovoltaic cells because of their chemical and environmental stability and their electronic tunability (Cremer and Bäuerle, 2006; Cravino et al., 2006; Hiorns et al., 2006) [8–10]. Thiophene-fused polyheteroaromatic dyes have attracted increasing interest as organic semiconductors for various electronic device applications, such as organic field-effect transistors, organic photovoltaic devices, and organic light-emitting diodes (Takimiya et al., 2004; Anthony, 2006; Shinamura et al., 2011; Liang et al., 2008; Lloyd et al., 2007; Mühlbacher et al., 2006) [11–16]. In this chapter, a series of Thiophene dyes are presented.

  Keywords

  π  →  π∗ transition; Electron donor; Sensitizers; Solar cells; Thiophene dyes

  Chapter Outline

  1. 16.1 Synthesis of Thiophene Dyes
  2. 16.2 Application of Thiophene Dyes
  3. References

  16.1. Synthesis of Thiophene Dyes

  Due to the application of Thiophene based dyes in dye-sensitized solar cells and photovoltaic cells [1 –16 ], several studies have been done on the synthesis of these compounds. A series of Thiophene dyes were synthesized for application in dye-sensitized solar cells (DSSCs). First, the precursor aldehydes 2a–d were prepared in fair to excellent yields (26%–84%), by Suzuki–Miyaura coupling of 5-bromothieno [3,2-b ]Thiophene-2-carbaldehyde 1 with commercially available heterocyclic boronic acids. The final push–pull conjugated dyes 3a–d were synthesized by Knoevenagel condensation of the corresponding aldehyde precursors 2a–d with cyanoacetic acid in refluxing ethanol, using piperidine as catalyst (Scheme 16.1 ) [17] . The UV–Vis spectra of dyes 3 were provided in ethanol at room temperature (Fig. 16.1 ). All dyes exhibited a strong and broad band between 364 and 433  nm that can be assigned to an intramolecular charge transfer (ICT) process between the donor and acceptor groups, which depends on the heterocyclic group linked to the thienoThiophene spacer. The addition of a 2-hexylThiophene unit, as seen in dye 3b , induced a bathochromic shift in the longest wavelength absorption of 34  nm compared with dye 3a . This result can be explained having in mind that the incorporation of an additional Thiophene ring increases the charge transfer properties in a push–pull compound because of the bathochromic effect of sulfur, the partial decrease of aromatic character of the Thiophene heterocycle, and the increase of the conjugation [18 ,19 ]. On the other hand, compound 3d , having an N -methyl pyrrole donor unit exhibited a 65  nm hypsochromic shift of absorption maxima compared with compound 3a functionalized with a Thiophene donor moiety. That can be explained by realizing that the pyrrole electron pair is involved in the aromatic system and, thus, not available for delocalization to the cyanoacetic acceptor group resulting in an increased energy gap between HOMO and LUMO orbitals [20 –22

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  Thiophene and Its Derivatives, Volume 44, Part 4

  • Salo Gronowitz(Author)
  • 2009(Publication Date)
  • Wiley-Interscience

    (Publisher)

  These volumes werc intcnded to be of intercst to all organic and medicinal chemists, as well as to those whose particular concern is heterocyclic chemistry. I t has become increasingly clear that this arbitrary distinction created as many problems as it solves, and we have therefore elected to discontinue the more recently initiated series General Heterocyclic Chemistry, and to publish all forthcoming volumes in the general area of heterocyclic chemistry in The Chemistry of Heterocyclic Compounds series. Deparrmenr 14 Chemisrry Princeton D’niorrsity Princeton, New Jersey EDWARD C. TAYLOR vii This Page Intentionally Left Blank In 1952, in the first volume of The Chemistry of Heterocyclic Compounds, Howard D. Hartough described the state of research on the chemistry of Thiophene and its derivatives up to 1950. Selenophene and tellurophene were also included in this monograph, which, except for two chapters, was written by Hartough alone. When this book was written, the explosive development triggered by the commercial process for Thiophene from butane and sulfur, developed by Socony-Vacuum Oil Company in the 194Os, had just begun. The enormous amount of work carried out on this important aromatic five-mem- bered heterocycle since 1950 makes it of course impossible for one person to cover all aspects, and an able group of specialists were assembled from all over the world to treat the entire field. This makes some minor overlaps between chapters unavoidable, but I think it is important to treat some topics from different angles of approach. Because of the wealth of results and the rather large number of contributors, these volumes are not as strictly organized as some previous volumes in this series, but can be considered as a collection of topics on Thiophene chemistry.

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  Conjugated Objects

  Developments, Synthesis, and Applications

  • Atsushi Nagai, Koji Takagi, Atsushi Nagai, Koji Takagi(Authors)
  • 2017(Publication Date)
  • Jenny Stanford Publishing

    (Publisher)

  n ]phenacene. Nevertheless, these compounds are described as heteroacenes for the sake of expedience in this chapter.

  Fig. 2.1 Structures of [n ]acenes, [n ]phenacenes, and [n ]helicenes.

  Fig. 2.2 Molecular structures of pentacyclic thienoacenes.

  This chapter will briefly survey [n ]acenes, [n ]heli cenes, and their heterocyclic analogues mainly from the viewpoint of synthetic methods. These compounds have been known over 100 years and been synthesized via a variety of strategies. Accordingly, there have been some excellent review articles and books which cover these compounds comprehensively. On the other hand, this chapter will describe the selected methods which have been historically significant or recently developed (mainly in this century) for the readers who become interested in fused polycyclic aromatic compounds. In addition to the synthetic methods, their properties and applications as organic functional materials are also described briefly. This chapter also covers heteroacenes and heterohelicenes containing silole or phosphole ring(s), which are not aromatic rings, since they are known to exhibit excellent optical/optoelectronic properties.

  2.2 [n jAcenes

  2.2.1 Introduction

  Numerous studies on acenes have been conducted for understanding their electronic structures, stability, aromaticity as well as for developing their application to organic electronics. With an increase in the number of fused benzene rings, the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) energy gaps decrease.4 In addition, the aromaticity per ring and stability are also decrease with the number of fused benzene rings. This trend can be understood qualitatively by the aromatic sextet proposed by Clar.5 According to the Clar’s theory, [n ]acenes possess only one aromatic sextet ring (Fig. 2.3 ). Thus, the aromaticity is shared among the rings, resulting in lower aromaticity per ring and lower stability for higher [n ]acenes. In fact, pentacene has been known to be very sensitive to oxygen and light to give the endoperoxide 4 or the dimer 5 (Scheme 2.1 ). The lower stability as well as low solubility of hexacene, heptacene, and higher [n ]acenes has prevented them from being isolated and well-characterized until recently. Accordingly, there have been a limited number of reports on them, and the synthesis of higher acenes is still a challenging goal.6 Although a huge number of synthetic methods have been developed for lower [n ]acenes (n < 3), this chapter will focus on higher [n ]acenes (n

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  • Gordon Gribble, J. Joule, Gordon W. Gribble(Authors)
  • 2009(Publication Date)
  • Elsevier Science

    (Publisher)

  Moreover, a detailed study of the chirality in alternating phenylene–biThiophene polymers having alkyloxy side-chains has been performed <07MAC8142>. Thiophene polymers incorporating naphthalene or methano[10]annulene units have also been prepared and studied, and the latter material displayed enhanced charge delocalization <07OL3041>. S S N S N C 16 H 33 C 16 H 33 n 86 S NC CN S O O O O H 21 C 10 O OC 10 H 21 n 87 S N N S S S O O O O 88 n S S O O O O n N S N N S N 89 5.1.6 Thiophene DERIVATIVES IN MEDICINAL CHEMISTRY A series of Thiophene-2-hydroxamic acids, among others the system 90 , have been prepared using Suzuki coupling as one of the key transformations, and have been identified as histone deacetylase (HDAC) inhibitors <07BMCL363>, while a related set of 5-(pyrazol-3-yl)-Thiophene-2-hydroxamic acid did also display similar effects <07BMCL370>. Moreover, compound 91 has been evaluated as a potent GLU K5 kainate receptor antagonist <07JMC1558>. Other studies of Thiophenes derivatives with biological effects encompass for instance design of Thiophene containing acylguanidines as BACE1 inhibitors aiming at preventing formation of amyloid plaques <07BMCL5353>, evaluation of Thiophenes bearing for example tetrazole units as carboxylic acid mimetics for inhibition of protein tyrosine phosphatase 1B <07BMCL2913>, or identification of the molecule 92 as an HCV inhibitor <07BMCL3905>. In addition, Thiophenes with aryl groups bearing hydrophilic side-chains have been evaluated as inhibitors of the glycine transporter GlyT1 <07BMCL5233>. A study of anthranilamides based on Thiophene-2-carboxylic acids led to discovery of orally available 112 T. Janosik and J. Bergman inhibitors of factor Xa en route to new therapeutic agents for thrombotic disorders <07JMC2967>, whereas amides based on Thiophene-2-acetic acid have been screened for antitubercular effects <07BMCL6895>.

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