15 research outputs found

    D-π-D chromophores based on dithieno[3,2-b:2′,3'-d]thiophene (DTT) : potential application in the fabrication of solar cell

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    In this work, four stable dithieno[3,2-b:2′,3'-d]thiophene-based π-extended molecules were designed and synthesized via a Pd-catalysed Sonogashira coupling reaction. The structures of these symmetrical compounds, including dithieno[3,2-b:2′,3'-d]thiophene (DTT) as the π-center and various donor (D) groups, were determined on the basis of NMR spectral data, elemental analysis, and X-ray crystallography. The photo-physical properties of the DTT-based derivatives 2 were fully investigated in both solution and solid state. The notable optical features of their solid-state powders showed significant red-shift in comparison with the luminescence of their dilute dichloromethane solutions. These results combined with the theoretical calculations indicate that they are promising candidates for the several applications in electronic and optoelectronic devices, as well as organic dyes for solar cells

    Synthesis and conformations of [2.n]metacyclophan-1-ene epoxides and their conversion to [n.1]metacyclophanes

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    A series of syn- and anti-[2.n]metacyclophan-1-enes have been prepared in good yields by McMurry cyclizations of 1,n-bis(5-tert-butyl-3-formyl-2-methoxyphenyl)alkanes. Significantly, acid catalyzed rearrangements of [2.n]metacyclophan-1-enes afforded [n.1]metacyclophanes in good yield. The ratios of the products are strongly regulated by the number of methylene bridges present. The percentages of the rearrangement products increase with increasing length of the carbon bridges. Characterization and the conformational studies of these products are described. Single crystal X-ray analysis revealed the adoption of syn- and anti-conformations. DFT calculations were carried out to estimate the energy-minimized structures of the synthesized metacyclophanes

    Synthesis and Structure of 1,2-Dimethylene[2.10]metacyclophane and Its Conversion into Chiral [10]Benzenometacyclophanes: Synthesis and Structure of 1,2-Dimethylene[2.10]metacyclophane and Its Conversion into Chiral [10]Benzenometacyclophanes

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    Bromination of 5,21-di-tert-butyl-8,24-dimethoxy-1,2-dimethyl[2.10]metacyclophan-1-ene (MCP-1-ene; 1) with benzyltrimethylammonium tribromide exclusively afforded 1,2-bis(bromomethyl)-5,21-di-tert-butyl-8,24-dimethoxy[2.10]MCP-1-ene (2). Debromination of 2 with Zn and AcOH in CH₂Cl solution at room temperature for 24 h produced dimethylene[2.10]MCP 7 in 92 % yield, which is a stable solid compound. Compound 7 was treated with dimethyl acetylenedicarboxylate (DMAD) to provide 1,2-(3′,6′-dihydrobenzo)-5,21-di-tert-butyl-8,24-dimethoxy[2.10]MCP-4′,5′-dimethylcarboxylate (8) in good yield. Diels–Alder adduct 8 was converted into a novel and inherently chiral areno-bridged dimethoxy[2.10]MCP-4′,5′-dimethylcarboxylate 9, possessing C₁ symmetry, by aromatization with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). A new type of N-phenyl-maleimide substituted 1,2-(3′,6′-dihydrobenzo)-5,21-di-tert-butyl-8,24-dimethoxy[2.10]MCP-4′,5′-N-phenylmaleimide 10 was also synthesized from 7 through treatment with N-phenylmaleimide in toluene at 110 °C followed by aromatization with DDQ. Single-crystal X-ray analysis of 9 revealed the formation of a syn-isomer

    Synthesis, structures and conformational studies of 1,2-dimethyl[2.10]metacyclophane-1-enes

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    A series of 1,2-dimethyl[2.10]metacyclophan-1-enes (MCP-1-enes) containing different substituent groups has been synthesized to illustrate their conformational behavior. 4,22-dimethoxy-1,2-dimethyl[2.10]MCP-1-ene 3 was synthesized by a Grignard coupling reaction, Friedel-Crafts acylation reactions and McMurry coupling reaction from 1,10-dibromodecane. The formation of 4,22-dihydroxy-1,2-dimethyl[2.10]MCP-1-ene 4 was carried out by demethylation of compound 3 with boron tribromide at room temperature. The syn type conformation of 4 was characterized by X-ray diffraction and was found to form both intramolecular and intermolecular hydrogen bonds between the two hydroxyl groups. From this reaction an interesting compound [10]tetrahydrobenzofuranophane 5 was afforded on prolonging the reaction time. 5,21-diformyl-4,22-dihydroxy-1,2-dimethyl[2.10]MCP-1-ene 6 has been prepared from 4,22-dihydroxy-1,2-dimethyl[2.10]MCP-1-ene 4 by using the Duff method in the presence of hexamethylenetetramine. Structural analysis by 1H NMR spectroscopy and X-ray diffraction confirmed that both the solution and the crystalline state of compound 6 adopts an anti-conformation which forms an intramolecular hydrogen bond between the formyl group and the hydroxyl group, which is an interesting finding for long carbon chain MCP compounds

    Synthesis and structure of a chiral areno-bridged [2.4]metacyclophane

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    © 2017 Elsevier Ltd The reductive coupling reaction of 1,4-bis(3-acetyl-5-tert-butyl-2-methoxyphenyl)butane 3 was carried out using TiCl 4 -Zn in pyridine followed by a McMurry coupling reaction to afford the compounds anti and syn 1,2-dimethyl[2.4]MCP-1-ene 4. Bromination of 4 with BTMA-Br 3 in dry CH 2 Cl 2 afforded the interesting compound 1,2-bis-(bromomethyl)-5,15-di-tert-butyl-8,18-dimethoxy[2.4]MCP-1-ene 6 and consecutive debromination with Zn and AcOH in CH 2 Cl 2 solution afforded the stable solid 5,15-di-tert-butyl-8,18-dimethoxy-1,2-dimethylene[2.4]MCP 7 in 89% yield. Compound 7 was conveniently employed in a Diels–Alder reaction with dimethyl acetylenedicarboxylate (DMAD) to provide 2-(3′,6′-dihydrobenzo)-5,15-di-tert-butyl-8,18-dimethoxy[2.4] MCP-4′,5′-dimethylcarboxylate 8 in good yield. Diels–Alder adduct 8 was converted into a novel and inherently chiral areno-bridged compound [2.4]MCP 9 by aromatization. The chirality of the two conformers was characterized by circular dichroism (CD) spectra of the separated enantiomer which are perfect mirror images of each other

    Demethylation of 5,n-di-tert-butyl-8,n-dimethoxy[2.n] metacyclophane-1-ynes with BBr3 to afford novel [n] benzofuranophanes

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    © 2016 Elsevier B.V. All rights reserved. Novel [n]benzofuranophanes (n = 8 & 10) 2a-b have been prepared by successive intramolecular cyclization from 5,19-di-tert-butyl-8,22-dimethoxy[n]metacyclophane-1-yne (syn-1a-b) by treatment with BBr 3 in CH 2 Cl 2 at room temperature for 8h. [2.n]Benzofuranophanes 2a-b were also obtained by treatment of 1,2-di-endo-bromo-5,19-di-tert-butyl-8,22-dimethoxy[n] metacyclophane (meso-3a-b) with BBr 3 in CH 2 Cl 2 by using the same reaction conditions. 1 H NMR spectra of 2a-b reveals the formation of intramolecular hydrogen bonding between hydroxyl proton with the oxygen of the furan moiety and X-ray analysis shows that the lengths between H (OH) and O (furan) are 1.981 and 1.823 Å, respectively. The conformation of [8]benzofuranophane 2a in solution is rigid with restricted rotation around the diaryl linkage rather than [10] benzofuranophane 2b because of weak intramolecular hydrogen bonding and the short length of the cross-linking chain

    Pyrene-based color-tunable dipolar molecules: Synthesis, characterization and optical properties

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    © 2018 Elsevier Ltd A controllable regioselective approach to achieve dipolar functionalization at the active sites (1,3-positions) and K-region (5,9-positions) of pyrene is demonstrated. Following this strategy, a set of dipolar 1,3-diphenyl-5,9-di(4-R-phenylethynyl)pyrenes were synthesized and systematically investigated by 1 H/ 13 C NMR spectroscopy, X-ray crystallography, electronic spectra, as well as by theoretical calculations. By adjusting the substituents at the 5,9-positions of pyrene, the pyrene-based dipolar molecules 4 (H, F, OMe, CN, CHO, NMe 2 ) exhibit tunable optical properties with a wide emission band from blue (437 nm) to orange-red (571 nm)

    D-π-D chromophores based on dithieno[3,2-b:2',3'-d]thiophene (DTT): Potential application in the fabrication of solar cell

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    © 2016 Elsevier LtdIn this work, four stable dithieno[3,2-b:2',3'-d]thiophene-based π-extended molecules were designed and synthesized via a Pd-catalysed Sonogashira coupling reaction. The structures of these symmetrical compounds, including dithieno[3,2-b:2',3'-d]thiophene (DTT) as the π-center and various donor (D) groups, were determined on the basis of NMR spectral data, elemental analysis, and X-ray crystallography. The photo-physical properties of the DTT-based derivatives 2 were fully investigated in both solution and the solid state. The notable optical features of their solid-state powders showed significant red-shifts in comparison with the luminescence of their dilute dichloromethane solutions. These results combined with the theoretical calculations indicate that they are promising candidates for several applications in electronic and optoelectronic devices, as well as organic dyes for solar cells

    Collaborative Virtual Screening Identifies a 2-Aryl-4-aminoquinazoline Series with Efficacy in an In Vivo Model of Trypanosoma cruzi Infection

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    Probing multiple proprietary pharmaceutical libraries in parallel via virtual screening allowed rapid expansion of the structure-activity relationship (SAR) around hit compounds with moderate efficacy against Trypanosoma cruzi, the causative agent of Chagas Disease. A potency-improving scaffold hop, followed by elaboration of the SAR via design guided by the output of the phenotypic virtual screening efforts, identified two promising hit compounds 54 and 85, which were profiled further in pharmacokinetic studies and in an in vivo model of T. cruzi infection. Compound 85 demonstrated clear reduction of parasitemia in the in vivo setting, confirming the interest in this series of 2-(pyridin-2-yl)quinazolines as potential anti-trypanosome treatments
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