非共轭多烯炔系统的环芳构化:通过由1- [2- {4-(2-烷氧基甲基苯基)丁-1,3-生成的双基团合成5 H-苯并[ d ]芴[3,2- b ]吡喃二炔基}]苯基戊烷-2,4-二炔-1-醇和1,2-二氢苯二自由基的捕集证据
摘要:
非共轭四炔1经历热分子内环化反应生成非苯并双自由基(23),然后在25°C进行自由基环芳构化,以提供7-脱氢-5 H-苯并[ d ]氟[3,2- b ]吡喃单自由基(24)和烷基(25)。24的氢原子提取得到5 H-苯并[ d ]芴[3,2- b ]吡喃(3),可通过与25反应转化为4。另一方面,2得到5 H-芴醇(5),表明形成了1,2-二氢苯双自由基中间体(28和29)。这些自由基通过与芳族二烯,蒽反应而被捕获为相应的Diels-Alder型产物。
Silole-Acetylene π-Electronic Systems with Low Bandgaps: Synthesis, Structure, and UV-vis Absorption Spectra of 2,5-Diethynylsiloles Derivatives and Their Polymers
作者:Shigehiro Yamaguchi、Kazuo Iimura、Kohei Tamao
DOI:10.1246/cl.1998.89
日期:1998.1
A series of 2,5-diethynylsilole derivatives and their polymers, prepared by the Stille coupling reaction, show unique optical properties such as long-wavelength absorptions in their UV-vis absorptionspectra.
Cycloaromatization of a non-conjugated polyenyne system: Synthesis of 5H-benzo[d]fluoreno[3,2-b]pyrans via diradicals generated from 1-[2-{4-(2-alkoxymethylphenyl)butan-1,3-diynyl}]phenylpentan-2,4-diyn-1-ols and trapping evidence for the 1,2-didehydrobenzene diradical
Non-conjugated tetraynes 1 undergo thermal intramolecular cyclization to non-benzenoid diradicals (23) followed by radical cycloaromatization at 25 °C to provide 7-dehydro-5H-benzo[d]fluoreno[3,2-b]pyran monoradical (24) and alkyl radicals (25). Hydrogen abstraction of 24 gives 5H-benzo[d]fluoreno[3,2-b]pyrans (3) which are converted to 4 by reaction with 25. On the other hand, 2 gives 5H-fluorenol (5), indicating
非共轭四炔1经历热分子内环化反应生成非苯并双自由基(23),然后在25°C进行自由基环芳构化,以提供7-脱氢-5 H-苯并[ d ]氟[3,2- b ]吡喃单自由基(24)和烷基(25)。24的氢原子提取得到5 H-苯并[ d ]芴[3,2- b ]吡喃(3),可通过与25反应转化为4。另一方面,2得到5 H-芴醇(5),表明形成了1,2-二氢苯双自由基中间体(28和29)。这些自由基通过与芳族二烯,蒽反应而被捕获为相应的Diels-Alder型产物。
Novel Classes of Alkynyliodonium Salts and Their Applications: The Synthesis of Substituted 1,3-Diynyliodonium Triflates, R - C≡C - C≡C - I???? - Ph<sup>-</sup>OTf, and Their Reaction with Triphenylphosphine
作者:Peter J. Stang、Jörg Ullmann
DOI:10.1055/s-1991-26681
日期:——
Reaction of butadiynyltrialkyltins 1 with cyano(phenyl)iodonium triflates 2 yields 1,3-diynyl(phenyl)iodonium triflates 3, a hitherto unknown class of functionalized diacetylenes. Additionally, the reaction of 3 with triphenylphosphine is described.
Non-conjugated thienyl tetrayne derivatives 1-3 are prepared as novel building block for the construction of indenothiophenone derivatives. Oxidation of 1-3, followed by cycloaromatization of the corresponding ketone derivatives 13-15 proceeds smoothly to afford indenothiophenone derivatives 16-21 in good yields. (C) 2005 Elsevier Ltd. All rights reserved.
Synthesis of Indeno[1,2-b]phenanthrene-Type Heterocycles by Cycloaromatization of Acyclic Non-conjugated Benzotetraynes