Synthesis Of Thiophenes Research Articles

A one-pot multicomponent synthesis of polysubstituted thiophenes via the reactions of an isocyanide, α-haloketones, and β-ketodithioesters in water

Abstract An efficient synthesis of polysubstituted thiophene derivatives is achieved via the multicomponent reaction of β-ketodithioesters, α-haloketones, and cyclohexylisocyanide in aqueous medium.

Synthesis of Dihydrothiophenes and Thiophenes by the Strategic Use of 2‐Vinylidene‐1,3‐dithiolane as a Masked Thiolate Anion

AbstractDifferently substituted 4‐(1,3‐dithiolan‐2‐ylidene)but‐1‐ynes were conveniently converted into the corresponding thiophenes and dihydrothiophenes in good to high yields under mild conditions. 1,3‐Dithiolan‐2‐ylidene acted as a masked thiolate anion and underwent tandem fragmentation and 5‐exo‐dig annulation with an alkyne moiety to form the five‐membered sulfur heterocycles.

Synthesis and Characterization of Thiophene and Thiazole Containing Polymers

In this study, bis(thiophene)-bis(ethylenedioxythiophene)-3,3′-dinonylthiazole (ThEdNBTEdTh) comonomer was obtained by using organometallic polycondensation mediated by organotransition metal complexes. The properties of electrochemically obtained poly[bis(thiophene)-bis(ethylenedioxythiophene)-3,3′-dinonylthiazole] (P[ThEdNBTEdTh]) from this comonomer were characterized by electrochemical techniques such as voltammetry and electrochemical impedance spectroscopy (EIS). Oxidative polymerization of ThEdNBTEdTh was carried out in dichlorometane onto a platinum electrode. Effect of polymerization charge on the redox behaviour of polymer films was investigated and these films were further characterized by ATR-FTIR, UV-Visible and fluorescence spectrophotometric measurements. EIS studies revealed that high capacitance values observed in the lower frequency region and proposed electrical equivalent circuit was applied to the experimental data to correlate the results, obtain the parameter of each element and explain the interface between the Pt/P[ThEdNBTEdTh/Bu4NPF6 system. Results showed that polymer has low oxidation potential, low band gap (1.67 eV) and good stability in the oxidized state and it shows p- and n-dopable properties. n-doping was verified experimentally by ex-situ FT-IR spectroelectrochemical measurements. The measured capacitance values are quite promising for supercapacitor applications.

3+3] Annulation of donor–acceptor cyclopropanes with mercaptoacetaldehyde: application to the synthesis of tetrasubstituted thiophenes

A conceptually new method for synthesis of tetrasubstituted thiophenes in two steps from trans-2-aroyl-3-aryl-cyclopropane-1,1-dicarboxylates and 1,4-dithiane-2,5-diol has been developed. It involves AlCl3-mediated [3+3] annulation of the cyclopropane-derived 1,3-zwitterionic intermediates with in situ generated mercaptoacetaldehyde, followed by DBU-induced rearrangement of the resulting tetrahydrothiopyranols. The target thiophenes are produced in 55-82% yields.

New Approaches for the Use of Acetoacetanilide in the Synthesis of Thiophenes and Their Fused Derivatives with Anti-Tumor Activity

Acetoacetanilide derivatives 1a-c reacted with either malnonitrile or ethyl cyanoacetate and elemental sulfur to give the thiophene derivatives 3a-f. The reactivity of 3a towards some chemical reagents to give thiophene, theino[2,3-b]pyridine, thieno[2,3-c]pyrimidine and coumarin derivatives was studied. The anti-tumor evaluation of the newly synthesized compounds against the three human tumor cells lines namely breast adenocarcinoma (MCF-7), non-small cell lung cancer (NCI-H460) and CNS cancer (SF-268) showed that compounds 8a, 8b and 14 exhibit higher inhibitory effects towards the three tumor cell lines than the positive control doxorubicin.

NBS-mediated sequential one-pot synthesis of multifunctionalized thiazoles and thiophenes from 1,3-dicarbonyl compounds and mercaptonitrile salts

A NBS-mediated sequential one-pot synthesis of multifunctionalized thiazoles and thiophenes from 1,3-dicarbonyl compounds and mercaptonitrile salts has been developed under mild conditions. This transformation involves sequential bromination/SN2 alkylation/Thorpe–Ziegler cyclization/regio-selective elimination of a –COR group, affording the desired products in moderate to good yields. The sequence of the leaving reactivity of –COR groups was determined and a possible mechanism was proposed.

Synthesis of an H-aggregated thiophene–phthalimide based small molecule via microwave assisted direct arylation coupling reactions

Abstract We report on the design, optimized synthesis, and characterization of a thiophene–phthalimide based small molecule. We show that microwave irradiation is a useful technique to accelerate direct arylation cross-coupling reactions, and that the thiophene–phthalimide architecture can lead to face-to-face intermolecular π-stacking, resulting in pronounced blue shifts in the absorption maximum upon a solution to condensed state transition.

Aspects for Thiocarbamoylation: Synthesis and Pharmacological Screening of Novel Thiophene, Thiadiazole and Pyrazole Derivatives

Aspects for Thiocarbamoylation: Synthesis and Pharmacological Screening of Novel Thiophene, Thiadiazole and Pyrazole Derivatives

Atom-Economic Syntheses of Thiophenes and Bithiophenes

Atom-Economic Syntheses of Thiophenes and Bithiophenes

Synthesis and Properties of Thiophene and Dithiin Functionalized Tetrathiafulvalenes

Syntheses of two analogues of tetrathiafulvalene (TTF), fused to 1,4-dithiin and thiophene rings, substituted with thiophene moieties, have been illustrated. The syntheses were accomplished through the reaction of a 1,8-diketone with phosphorus pentasulfide or Lawesson's reagent in boiling dry toluene. Conversion of the thioketones to their the oxo forms with mercury (II) acetate, was followed by self-coupling in freshly distilled boiling triethyl phosphite. Attempts for their electro-polymerizations through the thiophene groups at the peripherals were unsuccessful. Computational chemistry studies revealed that the thiophene groups did not exhibit enough spin densities to perform polymerization. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

The Knoevenagel reactions of pregnenolone with cyanomethylene reagents: Synthesis of thiophene, thieno[2,3-b]pyridine, thieno[3,2-d]isoxazole derivatives of pregnenolone and their in vitro cytotoxicity towards tumor and normal cell lines

The reaction of pregnenolone with either 2-aminoprop-1-ene-1,1,3-tricarbonitrile or 3-oxo-3-phenylpropanenitrile gave the Knoevenagel condensation products 3 and 6, respectively. Separation of the E and Z isomeric compounds of 3 and 6 together with their structure elucidation were carried out. Some chemical transformations of the latter products were carried out and the cytotoxicity of the newly obtained products was evaluated against some cancer cell lines and a human normal cell line. The results indicated that compounds 15, 17a, 18 and 20e among the tested compounds showed the highest cytotoxicity against the cancer cell lines.

Synthesis and Antitumor Activity of New Polysubstituted Thiophenes and 1,3,4‐Thiadiazoles Incorporating 2,6‐Pyridine Moieties

The versatile multifunctional unreported pyridine‐2,6‐bis(2‐cyano‐N‐phenyl‐3‐oxopropanethioamide) (3) was prepared starting from pyridine‐2,6‐bis‐(3‐oxopropanenitrile) (1). Several new series of polysubstituted thiophenes and 1,3,4‐thiadiazoles incorporating 2,6‐pyridine moiety were efficiently synthesized. The newly synthesized compounds were evaluated for their in vitro anticancer activity against human cancer cell lines: hepatocellular liver carcinoma (HEPG2) and Caucasian breast adenocarcinoma (MCF‐7). Some of the newly synthesized compounds exhibited better activity than doxorubicin as a reference drug.

New approaches for the synthesis of pyrazole, thiophene, thieno[2,3-b]pyridine, and thiazole derivatives together with their anti-tumor evaluations

The reaction of cyanoacetylhydrazine (1) with acetylchloride (2) gave the N-acyl derivative 3. The latter underwent ready cyclization in sodium ethoxide to give the pyrazole derivative 4 which was the key compound for the synthesis of thiophene, thieno[2,3-b]pyridine, and thiazole derivatives. The anti-tumor evaluations of the newly synthesized products against the three human tumor cell lines, namely, breast adenocarcinoma (MCF-7), non-small cell lung cancer (NCI-H460), and CNS cancer (SF-268), were studied. Some of these compounds were found to exhibit much higher inhibitory effects toward the three tumor cell lines than the reference doxorubicin. Molecular modeling of the four compounds 12c, 12f, 16a, and 16d, which showed the maximum inhibitory effect, were done.

Thiophenes from Viktor Meyer to Poly(Thiophene) Some Reactions and Synthesis

Reactions of thiophenes and the synthesis of thiophenes are reviewed in this article that presents more than 80 schemes outlining important discoveries in the chemistry of this heterocycle. The story comes full circle with the determination of the structure of the “impurity” that led to the mysterious blue color more than 130 years ago.

Optical limiting materials: Synthesis, electrochemical and optical studies of new thiophene based conjugated polymers carrying 1,3,4‐oxadiazole units

AbstractIn this communication we report synthesis of three new donor‐acceptor (D–A) type conjugated polymers carrying 1,3,4‐oxadiazole moiety and thiophene unit with different side groups at its 3,4 positions (4‐methoxybenzyl:P1, 3‐methylbenzyl:P2 and 4‐nitrobenzyl:P3) through polycondensation route using a series of newly synthesized monomers. The structures of new monomers and polymers were confirmed by NMR, FTIR spectroscopic methods followed by elemental analysis. Further, molecular weight and thermal stability were determined using gel permeation chromatography and thermogravimetric analysis. The linear optical and electrochemical properties of polymers were investigated by UV–vis absorption, fluorescence spectroscopic, and cyclic voltammetric studies. The polymers P1–P3 were found to be thermally stable and their electrochemical band gaps were determined to be 1.98, 2.14, and 2.18 eV respectively. Further their nonlinear optical properties were investigated by Z‐scan method using 532 nm, 7 ns laser pulses. The results reveal that they possess good optical limiting behavior due to effective three‐photon absorption (3PA) with absorption coefficient 2.5 × 10−24 m−3W2, 1.6 × 10−24 m−3W2, and 1.0 × 10−24 m−3W2. POLYM. ENG. SCI., 2013. © 2013 Society of Plastics Engineers

Synthesis of Thiophene and NO-Curcuminoids for Antiinflammatory and Anti-Cancer Activities

In search of better NSAIDs four novel nitric oxide donating derivatives of curcumin (compounds 9a–d), and four thiophene curcuminoids (compounds 10a–c, 11) have been synthesised. The cytotoxic effects of these compounds along with the lead compound curcumin (7) and their effect on the production of the reactive oxygen species nitric oxide and pro-inflammatory cytokines IL-1β, TNF-α and chemokine CXCL-8 were evaluated using human monocytic THP-1 and colon adenocarcinoma CACO-2 cell lines. All of the nitric oxide donating curcuminoids 9a–d and the thiophene curcuminoids 10a–c and 11 were non-cytotoxic to THP-1 cells over a concentration range of 10-100 μM and compared with curcumin compounds 10b and 10c, were more toxic. In CACO-2 cells, 10b and 11 appeared to be non-toxic at 10 to 50 μM, whereas 10a and 10c were non-cytotoxic at 10 μM only. These results clearly indicate that the introduction of a nitroxybutyl moiety to curcumin and replacement of phenyl rings with thiophene units reduces the cytotoxic effect of the parent curcumin, whereas a methyl substituted thiophene increases the cytotoxic effects. In THP-1 cells, drugs 10a and 11 significantly decreased IL-1-β production at their non-cytotoxic concentrations, whereas, they did not decrease TNF-α production in CACO-2 cells. Compound 11 showed a significant decrease in CXCL-8 production.

Synthesis and Biological Evaluation of Thiophene-<i>C</i>-glucosides as Sodium-Dependent Glucose Cotransporter 2 Inhibitors

The synthesis and structure-activity relationship (SAR) of thiophene-C-glucosides have been explored, and the human sodium-dependent glucose cotransporter 2 (hSGLT2) inhibitory activities and rat urinary glucose excretion (UGE) effects of 3a-f were evaluated. As a result, they showed good hSGLT2 inhibitory activities and rat UGE effects. In particular, the chlorothiophene derivative 3f showed remarkable inhibitory activity against hSGLT2.

The Reaction of Cyclopentanone with Cyanomethylene Reagents: Novel Synthesis of Pyrazole, Thiophene, and Pyridazine Derivatives

The reaction of cyclopentanone with either malononitrile or ethyl cyanoacetate gave the corresponding condensated products. The latter underwent some heterocyclic reactions to give new pyrazole, thiophene, and pyridazine derivatives. The antitumor evaluation of the newly synthesized products against the three cancer cells, namely, breast adenocarcinoma (MCF‐7), nonsmall cell lung cancer (NCI‐H460), and CNS cancer (SF‐268) showed that some of them have high inhibitory effect towards three cell lines which is higher than the standard.

Blue emitting C2-symmetrical dibenzothiazolyl substituted pyrrole, furan and thiophene

The synthesis and photophysical properties of pyrrole, furan and thiophene substituted in their 2 and 5 positions by 2′-benzothiazolyl moieties have been investigated. The three species show deep-blue fluorescence with maxima in the 444–450 nm region, originating from excited states of π–π* character. The photoluminescence quantum yields were found to be higher for the pyrrole and furan compounds, 0.42 and 0.47 respectively, compared to the quantum yield of the thiophene species, 0.21. Light Emitting Devices were fabricated using the pyrrole species as 4% dopant in a 4,4′,4′′-tri(9-carbazoyl)triphenylamine emissive layer, or the same pyrrole species as a neat film. In low concentration of dopant, the device is characterised by deep-blue emission with CIE coordinates of x = 0.182, y = 0.185; on the other hand, a neat film of the dopant produces almost white light emission with CIE x = 0.381, y = 0.400 but at a cost of quantum efficiency due to self-quenching effects.

Synthesis and Electrochemical Characterization of Thiophenes with Pendant Fluorescent Terpyridine

A novel series of thiophenes with terpyridine pendant groups were synthesized by Steglich esterification in the presence of DCC/DMAP and the synthesized monomers were electrochemically polymerized onto microelectrodes using glassy carbon and carbon fiber as active electrode materials. Each pendant group has aliphatic spacers with different chain lengths affecting the movement of the terpyridine groups. The synthesized thiophene derivatives were characterized by electrochemical and spectroscopic methods. The electrochemical impedance spectroscopic measurements of polythiophene-terpyridine (PTh-Terpy) derivatives were given comparatively. The fluorescence properties of the compounds were observed; all compounds were fluorescent, with higher fluorescence intensity for the shorter chain length, and slightly reduced fluorescence relative to that of the free terpyridine fluorophore. Morphological characterization was achieved via scanning electron microscopy.