Linear C2-symmetric polycyclic benzodithiophene: efficient, highly diversified approaches and the optical properties
摘要:
Two facile approaches to two new series of the seven-rings fused benzodithiophene-based polycyclic aromatics are developed in good yields. (c) 2005 Elsevier Ltd. All rights reserved.
Synthesis and Properties of Dicyanomethylene-Endcapped Thienopyrrole-Based Quinoidal <i>S</i>,<i>N</i>-Heteroacenes
作者:Hua Jiang、Kazuaki Oniwa、Zhanqiang Xu、Ming Bao、Yoshinori Yamamoto、Tienan Jin
DOI:10.1246/bcsj.20170083
日期:2017.7.15
A new series of highly π-extended dicyanomethylene-endcapped quinoidal S,N-heteroacenes (JH-quinoids) fused with thiophene and pyrrole rings have been designed and synthesized. The π-extension of the central S,N-heteroacene cores gives rise to significant red-shifted absorption maxima in solution without being affected by the long alkyl groups. The absorption maximum of JH10 with the longest quinoidal backbone in the thin film significantly red-shifted to the near-infrared region of 1260 nm as compared to that in solution (880 nm), indicating the formation of strong intermolecular interaction in the solid state. JH-quinoids maintain sufficiently low LUMO energy levels in the range of −4.09∼−4.22 eV regardless of the fused ring systems and substituents, while the HOMO energy levels increase with extending the length of S,N-heteroacenes; the highest HOMO energy level of JH10 is as high as −5.18 eV owing to the contributions from the nitrogen atoms and chalcogen. The molecular geometries of JH-quinoids optimized from the DFT calculations indicate their complete planar backbones and the trend of HOMO and LUMO energy levels variation is in good agreement with the cyclic voltammetry results. Consequently, the present JH-quinoids should be promising candidates for ambipolar organic semiconductors.
Carbon nanobelts that consist of a loop of fully fused benzene rings are long-standing and challenging targets of organic synthesis and are key steps toward the ultimate synthesis of uniform carbonnanotubes (CNTs) of single chirality and predefined diameter. Herein, we report the synthesis of an unprecedented armchair carbon nanobelt and the first chiral carbon nanobelt, which represent sidewall segments
Catalytic Enantioselective Synthesis of Axially Chiral Polycyclic Aromatic Hydrocarbons (PAHs) via Regioselective C–C Bond Activation of Biphenylenes
作者:Hideaki Takano、Natsumi Shiozawa、Yoshitane Imai、Kyalo Stephen Kanyiva、Takanori Shibata
DOI:10.1021/jacs.9b12205
日期:2020.3.11
Chiral polycyclicaromatichydrocarbons (PAHs) are expected to have unusual physical properties due to their chirality and extremely expanded π-conjugated system. Indeed, PAHs are expected to be useful as chiral recognizers and organic semiconductors. Therefore, a method for the synthesis of chiral PAHs is strongly desired. Although there are some reports of the enantioselective synthesis of helically
Benzotriazol-1-ylmethanol: An excellent bidentate ligand for the copper/palladium-catalyzed C-N and C-C coupling reaction
作者:Rajeev R. Jha、Jaspal Singh、Rakesh K. Tiwari、Akhilesh K. Verma
DOI:10.3998/ark.5550190.0014.219
日期:——
benzotriazole based N,O bidentate liga nds for the Cu-catalyzed N-arylation of πexcessive nitrogen heterocycles is described. This ligand accomplishes C-Ncoupling of Nheterocycles and C-Ccoupling of boronic acids with a variety of hindered, functionalized aryl/heteroaryl halides under mild reaction conditi ons in good to excellent yields. Using his ligandC-N and C-C (Suzuki) couplings with bromoarenes
描述了一种有效的基于苯并三唑的 N,O 双齿配体,用于铜催化的 π 过量氮杂环的 N-芳基化。该配体在温和的反应条件下以良好至极好的产率完成了杂环的 CN 偶联和硼酸与各种受阻的官能化芳基/杂芳基卤化物的 CC 偶联。使用他的配体 CN 和 CC (Suzuki) 与溴芳烃偶联可以在较少的催化剂负载下进行。一系列失活和受阻的芳基卤化物可以干净地反应,以高产率提供功能化的联芳基衍生物。
2-(1-Benzotriazolyl)pyridine: A Robust Bidentate Ligand for the Palladium-Catalyzed CC (Suzuki, Heck, Fujiwara-Moritani, Sonogashira), CN and CS Coupling Reactions
作者:Akhilesh K. Verma、Rajeev R. Jha、Ritu Chaudhary、Rakesh K. Tiwari、Abhinandan K. Danodia
DOI:10.1002/adsc.201200583
日期:2013.2.1
designed and employed for the palladium-catalyzed CC (Suzuki, Heck, Fujiwara–Moritani, and Sonogashira), CN and CS coupling reactions. The ligand was found to be inexpensive, thermally stable, easy to synthesize from easily accessible starting materials on a multigram scale, show simplicity in use, and robustness in application, making this ligand effective for different coupling reactions. Suitably, the
设计了一种新型的双齿配体1-(吡啶-2-基)-1 H-苯并[ d ] [1,2,3]三唑,并用于钯催化的CC(Suzuki,Heck,Fujiwara– Moritani和Sonogashira),CN和CS偶联反应。发现该配体便宜,热稳定,易于以几克规模由容易获得的起始原料合成,显示出使用简单性和在应用中的坚固性,从而使该配体对于不同的偶联反应有效。适当地,苯并三唑环的NN键的供体能力和吡啶环的N上的孤对电子增强了配体的二齿能力。