Triflic acid-Mediated Expedient Synthesis of Benzo[<i>a</i>
]fluorenes and Fluorescent Benzo[<i>a</i>
]fluorenones
作者:Mou Mandal、Rengarajan Balamurugan
DOI:10.1002/adsc.201701516
日期:2018.4.3
presented to access benzo[a]fluorenes by a triflic acid promoted cationic cycloisomerization of enynones in presence of trimethyl orthoformate under metal‐free conditions. In the absence of trimethyl orthoformate, the same reaction results in benzo[a]fluorenones. All the synthesized benzo[a]fluorenones are highly fluorescent in solution phase with high Stokes shift while the corresponding benzo[a]fluorenes
芴基聚芳烃是用于材料应用的著名化合物。在此,已经提出了一种通过原位乙缩醛形成的简单方法,该方法是在无金属条件下,在原甲酸三甲酯存在下,三氟甲磺酸促进乙炔的阳离子环异构化,从而获得苯并[ a ]芴。在不存在原甲酸三甲酯的情况下,相同的反应产生苯并[ a ]芴酮。所有合成的苯并[ a ]芴酮在溶液相中都具有高斯托克斯位移的高荧光性,而相应的苯并[ a ]芴类不是荧光性的。
Convergent Synthesis of Fluorene Derivatives by a Rhodium‐Catalyzed Stitching Reaction/Alkene Isomerization Sequence
作者:Masaki Nishida、Ryo Shintani
DOI:10.1002/chem.201901519
日期:2019.6.4
the synthesis of fluorenederivatives has been developed by devising a rhodium‐catalyzed stitching reaction/alkene isomerization sequence. The reactions proceed smoothly under mild conditions for a variety of substrate combinations, and extended π‐conjugation systems are also readily accessible by utilizing this synthetic method. Optical properties of the obtained fluorenederivatives have also been
Assembly of trifluoroethyl benzo[a]fluorenyl ether architecture directly from non-aromatic precursors (1,6-enynes) in the presence of aryldiazonium salts and 2,2,2-trifluoroethanol
作者:Hong Gao、Siwei Xiang、Limeng Zheng、Bingwei Zhou、Yunkui Liu
DOI:10.1016/j.tet.2023.133417
日期:2023.5
An efficient, chemoselective, and one-pot synthesis of trifluoroethyl benzo[a]fluorenyl ethers directly fromnon-aromaticprecursors (1,6-enynes) has been developed under transition metal-free conditions. Mechanistic studies disclosed that the reaction proceeded via an in situ generated HBF4-assisted intramolecular cycloisomerization of 1,6-enynes followed by a trifluoroethylation with 2,2,2-trifluoroethanol
在无过渡金属的条件下,开发了一种直接从非芳香族前体(1,6-烯炔)直接高效、化学选择性和一锅法合成三氟乙基苯并[ a ]芴基醚的方法。机理研究表明,该反应通过原位生成的 HBF 4辅助 1,6-烯炔的分子内环化异构化,然后用 2,2,2-三氟乙醇进行三氟乙基化来进行。