TTFs nonsymmetrically fused with alkylthiophenic moieties

• Rafaela A. L. Silva,
• Bruno J. C. Vieira,
• Marta M. Andrade,
• Isabel C. Santos,
• Sandra Rabaça,
• Dulce Belo and
• Manuel Almeida

Beilstein J. Org. Chem. 2015, 11, 628–637, doi:10.3762/bjoc.11.71

• ; supramolecular chemistry; tetrathiafulvalene (TTF); thiophene; Introduction Since the discovery of the first organic metals and superconductors the field of electronic molecular materials has been largely dominated by derivatives of the organic donor tetrathiafulvalene (TTF) [1]. More than one thousand TTF

• converted to transition metal complexes based on extended thiophene/TTF-fused dithiolene ligands. They were obtained by cross-coupling reactions between alkylated thio and oxo compounds. The incorporation of these alkyl groups in the thiophenic ring is expected to increase the solubility of these TTFs and

• analogous transition metals complexes, enabling their processing from solutions. Results and Discussion Synthesis The TTF donors fused non-symetrically with substituted thiophene moieties 1 and 2 were obtained by the cross coupling, in the presence of trimethyl phosphite, between compounds I and II and

Hetero-Diels–Alder reactions of hetaryl and aryl thioketones with acetylenic dienophiles

• Grzegorz Mlostoń,
• Paulina Grzelak,
• Maciej Mikina,
• Anthony Linden and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2015, 11, 576–582, doi:10.3762/bjoc.11.63

• of the products were determined based on the spectroscopic data. Thus, similar to hetero-Diels–Alder reactions with maleic anhydride [14], the C=C bond of the thiophene ring of 1h is part of the reactive heterodiene system. The reactions of 2b with thiobenzosuberone 1b and thiobenzosuberenone 1c were

Ruthenium-catalyzed C–H activation of thioxanthones

• Danny Wagner and
• Stefan Bräse

Beilstein J. Org. Chem. 2015, 11, 431–436, doi:10.3762/bjoc.11.49

• already in the pioneering work there are also examples using sulfur heterocycles such as thiophene derivatives [19]. Gratifyingly, the reaction of dimethyl-substituted thioxanthone 1b with the model olefin neohexene (3,3-dimethyl-1-butene, 4a) was successful and the product 1ba was obtained in 65% yield

Bis(vinylenedithio)tetrathiafulvalene analogues of BEDT-TTF

• Erdal Ertas,
• İlknur Demirtas and
• Turan Ozturk

Beilstein J. Org. Chem. 2015, 11, 403–415, doi:10.3762/bjoc.11.46

• charge transfer salts. The physical and electronic properties of their solid states were investigated [13][25][47][48][49]. We attempt here to provide a summary of the synthesis of differently functionalized and extensively π-electron delocalized conjugated TTF core dithiin- and thiophene-fused donor

• (LR) [50] or tetraphosphorus decasulfide (P4S10) [51] Although, in most cases, formation of 1,4-dithiins is the only result, or the major one, a thiophene formation can also take place [46]. So far, eighteen BVDT-TTF analogues have been synthesized (Figure 3). In 1996, we reported a convenient method

• of synthesizing fused 1,4-dithiin and thiophene ring systems, possessing functional groups such as Ph 4-MeOC6H4 and 4-O2NC6H4 (Scheme 1) [46]. The synthesis involved treatment of the diketone 6, produced through the reaction of the readily available dianion 5 [52] with α-haloketones, with Lawesson’s

IR and electrochemical synthesis and characterization of thin films of PEDOT grown on platinum single crystal electrodes in [EMMIM]Tf₂N ionic liquid

• Andrea P. Sandoval,
• Marco F. Suárez-Herrera and
• Juan M. Feliu

Beilstein J. Org. Chem. 2015, 11, 348–357, doi:10.3762/bjoc.11.40

• listed in Table 2. The absorption bands at 1339 cm−1 and 1415 cm−1 can be assigned to the asymmetric stretching, νas, of the SO2 moiety and the stretching of the thiophene ring in the oxidized state, respectively. Figure 7b shows that there are two potential regions where significant changes of the IR

• Figure 2. Also, the bands associated with the C=C bonds in the thiophene ring (1437 and 1469 cm−1) are negative. The trend of the IR intensity at 1437 cm−1 (Figure 7c) shows a slight decrease from −0.7 to −0.3V and an abrupt fall at higher potentials. This trend closely resembles the currents observed

• during the p-doping of PEDOT (Figure 3a), suggesting that the disappearance of the ν(C=C) stretching signal of the thiophene ring upon oxidation can be used to quantify the charge carriers inside the polymer. It seems that with increasing potential, the concentration of charge carriers (polarons

Functionalized branched EDOT-terthiophene copolymer films by electropolymerization and post-polymerization “click”-reactions

• Miriam Goll,
• Adrian Ruff,
• Erna Muks,
• Felix Goerigk,
• Beatrice Omiecienski,
• Ines Ruff,
• Rafael C. González-Cano,
• Juan T. Lopez Navarrete,
• M. Carmen Ruiz Delgado and
• Sabine Ludwigs

Beilstein J. Org. Chem. 2015, 11, 335–347, doi:10.3762/bjoc.11.39

• Thermo Fisher Scientific GmbH, Im Steingrund 4-6, 63303 Dreieich, Germany Department of Physical Chemistry, University of Málaga, 29071 Málaga, Spain 10.3762/bjoc.11.39 Abstract The electrocopolymerization of 3,4-ethylenedioxythiophene (EDOT) with the branched thiophene building block 2,2′:3′,2

• modification of the monomers. In addition to electropolymerization of simple conjugated monomers [15] more complex monomers which include different building blocks were presented. Roncali et al. used for example EDOT containing branched thiophene monomers [16][17]. In some of the more complex monomer systems

• the electropolymerization can be regarded as a crosslinking step [17][18]. Electropolymerization of monomer mixtures is another powerful tool to modify material properties. Among a variety of monomer mixtures including pyrrole and thiophene [19][20], 2,2’-bithiophene and pyrrole [21][22] and

Anionic sigmatropic-electrocyclic-Chugaev cascades: accessing 12-aryl-5-(methylthiocarbonylthio)tetracenes and a related anthra[2,3-b]thiophene

• Laurence Burroughs,
• John Ritchie,
• Mkhethwa Ngwenya,
• Dilfaraz Khan,
• William Lewis and
• Simon Woodward

Beilstein J. Org. Chem. 2015, 11, 273–279, doi:10.3762/bjoc.11.31

Sequential decarboxylative azide–alkyne cycloaddition and dehydrogenative coupling reactions: one-pot synthesis of polycyclic fused triazoles

• Kuppusamy Bharathimohan,
• Thanasekaran Ponpandian,
• A. Jafar Ahamed and
• Nattamai Bhuvanesh

Beilstein J. Org. Chem. 2014, 10, 3031–3037, doi:10.3762/bjoc.10.321

• versatile synthetic functionality for further derivatization reactions. The thiophene-derived alkynoic acid, 2d, provided the corresponding triazole analogs 4d and 4j in 79% and 73%, respectively. Likewise, the alkynoic acid derived from short and long linear alkyl chains also provided good yields (75–88

Palladium-catalyzed 2,5-diheteroarylation of 2,5-dibromothiophene derivatives

• Fatma Belkessam,
• Aidene Mohand,
• Jean-François Soulé,
• Abdelhamid Elias and
• Henri Doucet

Beilstein J. Org. Chem. 2014, 10, 2912–2919, doi:10.3762/bjoc.10.309

• -diheteroarylated thiophenes bearing two different heteroaryl units. Keywords: aryl halides; catalysis; C–H bond activation; direct arylation; heteroarenes; palladium; Introduction 2,2':5',2"-Terthiophene (or 2,5-di(2-thienyl)thiophene) (Figure 1) and many of its derivatives are important structures due to their

• et al. reported the Pd-catalyzed coupling of 2,5-dibromothiophene with 3-methoxythiophene to afford the corresponding terthiophene in 29% yield [37]. From 2,5-diiodothiophene and benzoxazole, using 5 mol % Pd(phen)2(PF6)2 catalyst, the 2,5-diheteroarylated thiophene was obtained in 89% yield by Murai

• et al. [38]. A fluorescent π-conjugate thiophene derivative bearing spiro[fluorene-9,4’-[4H]indeno[1,2-b]furan] substituents at C2 and C5 has been prepared in 46% yield by this reaction using Pd(OAc)2 (5 mol %) associated to PPh3 (10 mol %) as catalytic system [39]. A pyrrole derivative was coupled

Copper-promoted hydration and annulation of 2-fluorophenylacetylene derivatives: from alkynes to benzo[b]furans and benzo[b]thiophenes

• Yibiao Li,
• Liang Cheng,
• Xiaohang Liu,
• Bin Li and
• Ning Sun

Beilstein J. Org. Chem. 2014, 10, 2886–2891, doi:10.3762/bjoc.10.305

• reaction and its application in the synthesis of benzo[b]furan and benzo[b]thiophene derivatives is presented starting from readily available 2-fluorophenylacetylene derivatives. The key annulation step involves the hydration of the C–F bond of 2-fluorophenylacetylene derivatives followed by an

• intramolecular annulation to afford benzo[b]furan and benzo[b]thiophene derivatives. Moreover, structurally important 2,2'-bisbenzofuran scaffolds are provided in good yields. Keywords: annulation; benzo[b]furan; C–F activation; copper-promoted; heterocycle; Introduction The development of general and

• efficient methodologies for the synthesis of complex heterocycle skeletons has received much attention in the past decades. Among the most ubiquitous heterocyclic moieties in natural and bioactive products are the benzo[b]furan and benzo[b]thiophene units [1][2][3][4][5][6][7][8]. Despite the existence of

Synthesis of an organic-soluble π-conjugated [3]rotaxane via rotation of glucopyranose units in permethylated β-cyclodextrin

• Jun Terao,
• Yohei Konoshima,
• Akitoshi Matono,
• Hiroshi Masai,
• Tetsuaki Fujihara and
• Yasushi Tsuji

Beilstein J. Org. Chem. 2014, 10, 2800–2808, doi:10.3762/bjoc.10.297

• synthesized from 1 using sodium naphthalenide [27]. The reaction of the thus-formed monoalcohol with 2-bromo-3-(bromomethyl)thiophene (11) afforded thiophene-linked PM β-CD 12. Pd-catalyzed Stille cross-coupling of 12 with bithiophene 13 bearing a silyl-protected alkynyl group afforded trithiophene-linked PM

Solution processable diketopyrrolopyrrole (DPP) cored small molecules with BODIPY end groups as novel donors for organic solar cells

• Diego Cortizo-Lacalle,
• Calvyn T. Howells,
• Upendra K. Pandey,
• Joseph Cameron,
• Neil J. Findlay,
• Anto Regis Inigo,
• Tell Tuttle,
• Peter J. Skabara and
• Ifor D. W. Samuel

Beilstein J. Org. Chem. 2014, 10, 2683–2695, doi:10.3762/bjoc.10.283

• -diaza-s-indacene (BODIPY) units attached by thiophene rings have been synthesised having high molar extinction coefficients. These triads were characterised and used as donor materials in small molecule, solution processable organic solar cells. Both triads were blended with PC71BM as an acceptor in

• the triads, theoretical DFT and TDDFT calculations were performed. Keywords: BODIPY; diketopyrrolopyrrole; organic semiconductors; organic solar cells; thiophene; Introduction The discovery of photoinduced electron transfer from conjugated polymers to fullerene (C60), and the favourable

• with bis-vinylthienyl groups exceeded 4.5% [43]. Although, a few dyads and triads containing both the DPP and BODIPY core have been prepared [44][45][46], here we present the synthesis and characterisation of two novel BODIPY-DPP-BODIPY triads linked by thiophene bridges. These materials were tested in

Photochemical approach to functionalized benzobicyclo[3.2.1]octene structures via fused oxazoline derivatives from 4- and 5-(o-vinylstyryl)oxazoles

• Ivana Šagud,
• Simona Božić,
• Željko Marinić and
• Marija Šindler-Kulyk

Beilstein J. Org. Chem. 2014, 10, 2222–2229, doi:10.3762/bjoc.10.230

• formation of the photoproducts 8 and 10 can be explained by intramolecular cycloaddition and formation of resonance stabilized biradicals A/A’ followed by the 1,6-ring closure (Scheme 4). An 1,3-H shift, as in furan and thiophene derivatives [6], and rearomatization to fused oxazole derivatives B/B’ is not

• -vinylnaphtho[2,1-b]thiophene [6] occured, respectively. During chromatography on silica gel the tricyclic formiato derivative rel-(9S)-12 is formed from 8 (Scheme 5). In the 1H NMR spectrum the main diastereomer rel-(9S)-12a shows the signal of the formiato proton in the low field at 8.2 ppm. The signals from

Synthesis of new, highly luminescent bis(2,2’-bithiophen-5-yl) substituted 1,3,4-oxadiazole, 1,3,4-thiadiazole and 1,2,4-triazole

• Anastasia S. Kostyuchenko,
• Vyacheslav L.Yurpalov,
• Aleksandra Kurowska,
• Wojciech Domagala,
• Adam Pron and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2014, 10, 1596–1602, doi:10.3762/bjoc.10.165

• are prepared. Following a synthetic strategy, featuring the bottom-up approach, sequential structural elements are built, starting from a simple thiophene compound, until the target molecule is obtained, all in good yield. Supplementing the well established methods of oxadiazole and thiadiazole

• and Discussion Synthetic toolbox There are several approaches to the synthesis of 2,5-bis(2,2 '-bithiophen-5-yl)-1,3,4-oxadiazoles and 1,3,4-thiadiazoles. Transition metal-catalysed cross-coupling reactions, such as Stille, Suzuki etc. are typically used for the formation of thiophene–thiophene or

• azole–thiophene bonds [14][16][17]. However, the best results (higher yields, more facile purification, shorter reaction times) are obtained by the formation of the azole ring via appropriately functionalized bithiophenes [14][22]. Recently, we have developed a new method for the preparation of 3-alkyl

Pd/C-catalyzed aerobic oxidative esterification of alcohols and aldehydes: a highly efficient microwave-assisted green protocol

• Marina Caporaso,
• Giancarlo Cravotto,
• Spyros Georgakopoulos,
• George Heropoulos,
• Katia Martina and
• Silvia Tagliapietra

Beilstein J. Org. Chem. 2014, 10, 1454–1461, doi:10.3762/bjoc.10.149

• 90 to 120 °C, had to be applied for each substrate. Thiophene carboxaldehyde, for instance, afforded only a 45% desired ester yield at 100 °C, while the yield increased to 85% in the absence of any byproducts when the reaction temperature was raised to 120 °C (Table 2, entry 12). However, significant

Homochiral BINOL-based macrocycles with π-electron-rich, electron-withdrawing or extended spacing units as receptors for C₆₀

• Marco Caricato,
• Silvia Díez González,
• Idoia Arandia Ariño and
• Dario Pasini

Beilstein J. Org. Chem. 2014, 10, 1308–1316, doi:10.3762/bjoc.10.132

• the Hill equation [42] gave an average binding constant of 1600 M−1, thus confirming a higher affinity for the π-electron rich thiophene-derived spacer units. The Hill coefficient [43][44] suggests the presence of concomitant 1:1 and 1:2 C60:macrocycle complexes in solution. Even more interestingly

• . (R,R)-3b. [α]D25 +54 (c 0.0015, CH2Cl2); ESIMS m/z (%): 1043 ([M + Na]+, 100); 1H NMR (CDCl3, 200 MHz, 25 °C) δ 8.10 (s, 4H, binaphthyl), 7.89 (d, 4H, binaphthyl), 7.81 (s, 4H, thiophene), 7.38 (t, 4H, binaphthyl), 7.27 (m, 4H, binaphthyl), 7.16 (d, 4H, binaphthyl), 5.60 (dd, 8H, CH2), 3.27 (s, 12H

• NMR (CDCl3, 200 MHz, 25 °C) δ 8.10 (s, 6H, binaphthyl), 7.95–7.80 (m, 12H, binaphthyl + thiophene), 7.35 (t, 6H, binaphthyl), 7.5–7.1 (m, 12H, binaphthyl), 5.63 (s, 12H, CH2), 3.31 (s, 18H, OCH3); 13C NMR (CDCl3, 75 MHz, 25 °C) δ 161.2 (Cq), 154.9 (Cq), 138.7 (Cq), 134.3 (Cq), 133.3 (CH), 130.8 (CH

Hindered aryl bromides for regioselective palladium-catalysed direct arylation at less favourable C5-carbon of 3-substituted thiophenes

• Rongwei Jin,
• Charles Beromeo Bheeter and
• Henri Doucet

Beilstein J. Org. Chem. 2014, 10, 1239–1245, doi:10.3762/bjoc.10.123

• use of the congested aryl bromide 2-bromo-1,3-dichlorobenzene as coupling partner allows to modify the regioselectivity of the arylation of 3-substituted thiophene derivatives in favour of carbon C5. The coupling of this aryl bromide with a variety of 3-substituted thiophenes gave in all cases the

• desired 5-arylation products in moderate to good yields using only 0.5 mol % of a phosphine-free and air-stable palladium catalyst. Then, from these 5-arylthiophenes, a second palladium-catalysed C–H bond functionalization at C2 of the thiophene ring allows the synthesis of 2,5-diarylthiophenes with two

• aryls on thiophenes is an important research area in organic synthesis. The coupling of thiophene derivatives with aryl halides via a C–H bond activation/functionalisation [1][2][3][4][5][6][7][8][9][10][11][12] provides an environmentally attractive and cost-effective procedure for the preparation of a

Visible light mediated intermolecular [3 + 2] annulation of cyclopropylanilines with alkynes

• Theresa H. Nguyen,
• Soumitra Maity and
• Nan Zheng

Beilstein J. Org. Chem. 2014, 10, 975–980, doi:10.3762/bjoc.10.96

• developing new synthetic methods. This method has certainly passed this test as two pairs of heterocycle-containing alkynes underwent the [3 + 2] annulation with cyclopropylanilines uneventfully (15–18). The alkyne moiety at the C2 or C3 position of thiophene or pyridine showed similar reactivity towards the

Unusual polymorphism in new bent-shaped liquid crystals based on biphenyl as a central molecular core

• Anna Kovářová,
• Svatopluk Světlík,
• Václav Kozmík,
• Jiří Svoboda,
• Vladimíra Novotná,
• Damian Pociecha,
• Ewa Gorecka and
• Natalia Podoliak

Beilstein J. Org. Chem. 2014, 10, 794–807, doi:10.3762/bjoc.10.75

• behavior. The structural variations involved lateral substitution of the biphenyl core [9][10][11], lateral substitution of the outer benzene ring [12], substitution of the outer benzene for thiophene in the lengthening arms [13], introduction of siloxane [11][14][15], carbosilane [16][17][18][19

Isocyanide-based multicomponent reactions towards cyclic constrained peptidomimetics

• Gijs Koopmanschap,
• Eelco Ruijter and
• Romano V.A. Orru

Beilstein J. Org. Chem. 2014, 10, 544–598, doi:10.3762/bjoc.10.50

• -[4,5]deca-6,9-diene-3,8-diones (171) via a 5-exo-Michael addition, whereas DCM as solvent induced an intramolecular thiophene Diels–Alder reaction yielding tricyclic lactam 173. In an alternative approach an Ugi-protocol employing a resin-bound carbonate-based convertible isocyanide 174 (CCI) was

Silver and gold-catalyzed multicomponent reactions

• Giorgio Abbiati and
• Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

• synthetic strategy, a solution-phase parallel synthesis of 1,2-dihydroisoquinolines has been developed by Larock, providing a 105-membered library for biological assays [58]. Moreover, an extension to γ-ketoalkyne encompassed in diverse heterocyclic frameworks (quinoline, pyridine or benzo[b]thiophene) has

The Flögel-three-component reaction with dicarboxylic acids – an approach to bis(β-alkoxy-β-ketoenamides) for the synthesis of complex pyridine and pyrimidine derivatives

• Mrinal K. Bera,
• Moisés Domínguez,
• Paul Hommes and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2014, 10, 394–404, doi:10.3762/bjoc.10.37

• diphenic acid (12) in combination with methoxyallene (7), pivalonitrile (9) and thiophene-2-carbonitrile (10) in the three-component reaction (Scheme 2). Gratifyingly we were able to isolate the expected bis(β-ketoenamides) 13–15 in reasonable yields of 15–28%. Taking the number of individual steps into

• -(tributylstannyl)thiophene. Albeit the expected twofold coupling products 21 and 22 were obtained in only moderate yields, the presented approach nevertheless features a quite rapid access to these fairly complex heteroaromatic systems containing six conjugated aryl and hetaryl groups. Upon excitation with UV

• light (253 nm) compound 22 shows fluorescence with a maximum intensity at 378 nm (see Supporting Information File 1 for details). The photophysical properties of structurally related pyridine–thiophene conjugates were recently investigated in detail [55][57][58]. Next, we investigated the

The regioselective synthesis of spirooxindolo pyrrolidines and pyrrolizidines via three-component reactions of acrylamides and aroylacrylic acids with isatins and α-amino acids

• Tatyana L. Pavlovskaya,
• Fedor G. Yaremenko,
• Victoria V. Lipson,
• Svetlana V. Shishkina,
• Oleg V. Shishkin,
• Vladimir I. Musatov and
• Alexander S. Karpenko

Beilstein J. Org. Chem. 2014, 10, 117–126, doi:10.3762/bjoc.10.8

• nonnatural α-amino acids [11][12][13], more than fifteen isatins [14], and 1,3-dipolarophiles, e.g. α,β-unsaturated ketones [15][16][17], maleimides [18][19], benzo[b]thiophene-1,1-dioxide [20], bis(arylmethylidene)acetones and -cycloalkanones [21][22], 1,4-naphthoquinone [23], arylidenemalonodinitriles [24

Gold(I)-catalyzed domino cyclization for the synthesis of polyaromatic heterocycles

• Mathieu Morin,
• Patrick Levesque and
• Louis Barriault

Beilstein J. Org. Chem. 2013, 9, 2625–2628, doi:10.3762/bjoc.9.297

• benzothiophene 7 was isolated in 89% yield. The formation of this unforeseen product can be explained by the proposed mechanism illustrated in Scheme 2. The gold(I) complexation of alkyne 4 triggers the 5-exo-dig cyclization to produce intermediate 9. At this point, a nucleophilic addition of the thiophene unit

New developments in gold-catalyzed manipulation of inactivated alkenes

• Michel Chiarucci and
• Marco Bandini

Beilstein J. Org. Chem. 2013, 9, 2586–2614, doi:10.3762/bjoc.9.294

• obtained from moderate to good yields under microwave irradiation (DCE, Scheme 17c) [54]. Additionally, the stronger Lewis acid AuCl3/AgSbF6 was documented to catalyze the Markovnikov selective hydroarylation of aryl- and alkyl olefins with less-nucleophilic benzene derivatives and thiophene in good yields

• indoles to alkenes. Intermolecular [Au(III)]-catalyzed hydroarylation of alkenes with benzene derivatives and thiophene. a) Intramolecular [Au(III)]-catalyzed hydroarylation of alkenes. b) A SEAr-type mechanism was hypothesized by the authors. Intramolecular [Au(I)]-catalyzed hydroalkylation of alkenes