Nickel-Catalyzed Facile [2+2+2] Cyclotrimerization of Unactivated Internal Alkynes to Polysubstituted Benzenes
作者:Fei Xue、Ying Kai Loh、Xiaolu Song、Wei Jie Teo、J. Y. Darrence Chua、Jin Zhao、T. S. Andy Hor
DOI:10.1002/asia.201601469
日期:2017.1.3
A catalytic [2+2+2] cyclotrimerization of unactivated internal alkynes providing cyclotrimerization products in excellent yields with high regioselectivity is described. The transformation is accomplished by using a simple catalytic mixture comprising Ni(acac)2, an imidazolium salt and a Grignard reagent at room temperature or 60 °C for 20 min or 1 h.
Palladium‐Catalyzed Cycloisomerizations of Diarylacetylenes: Synthesis, Structures, and Physical Properties of Highly Substituted Naphthalenes and 8,8 a‐Dihydrocyclopenta[<i>a</i>]indenes
Depending on the electronic properties of their substituents, the major products generated by palladium‐catalyzed cycloisomerizations of diarylalkynes are either highlysubstituted 8,8a‐dihydrocyclopenta[a]indenes 3 or naphthalenes 4. The structures of these compounds were verified by X‐ray crystallographic analysis. Many functional groups tolerated the reaction conditions evaluated in this study.
根据其取代基的电子特性,二芳基炔烃的钯催化环异构化反应生成的主要产物是高度取代的8,8a-二氢环戊[ a ]茚3或萘4。这些化合物的结构通过X射线晶体学分析进行了验证。许多官能团耐受本研究中评估的反应条件。同位素标记的实验表明,加水在形成这两类化合物中都起着至关重要的作用。系统研究了环加合物3及其类似物的光物理和电化学性质,并将其与基于密度泛函理论的计算预测进行了比较。二氢环戊[一个]茚3在为固体或液体形式显示强发光,而环戊二烯并[一个]茚11j中实际上是无荧光。直接连接到化合物3的主链上的官能团会显着影响物理性能。芳基取代基引起的空间效应引起不同的发光现象,包括聚集诱导和增强的发射。
Synthesis of 2,5,8,11,14,17-Hexafluoro-hexa-<i>peri</i>- hexabenzocoronene for n-Type Organic Field-Effect Transistors
A fluorine-substituted hexa-peri-hexabenzocoronene was synthesized as a thermostable active material for n-type semiconductors. The LUMO and HOMO energy levels, estimated by UV-vis and photoelectron spectroscopy, were lower by 0.5 eV than those of hexa-peri-hexabenzocoronene. A field-effect transistor fabricated by vacuum sublimation showed n-type performance with a field-effect mobility of 1.6 x 10(-2) cm(2)/Vs and an on/off ratio of 10(4). The electron-withdrawing effect of the fluorine substituents changed the polarity from p-type to n-type.
Synthesis, Structure, and Photophysical Properties of Highly Substituted 8,8a-Dihydrocyclopenta[<i>a</i>]indenes
作者:Yao-Ting Wu、Ming-Yu Kuo、Yu-Ting Chang、Chien-Chueh Shin、Tsun-Cheng Wu、Chia-Cheng Tai、Tzu-Heng Cheng、Wei-Szu Liu
Hexa-peri-hexabenzocoronenes (HBCs) can be used as electron-donators in electron-transfer systems. The variation of the substitution pattern allows for the adjustment of electronic properties of the HBC core. The synthetic routes toward a series of thioether-substituted HBCs and the investigation of their electronic properties are described, as well as their reactions to the corresponding sulfones