1280219-84-2Relevant academic research and scientific papers
Br?nsted/Lewis Acid-Promoted Site-Selective Intramolecular Cycloisomerizations of Aryl-Fused 1,6-Diyn-3-ones for Diversity-Oriented Synthesis of Benzo-Fused Fluorenes and Fluorenones and Naphthyl Ketones
Mandal, Mou,Sakthivel, Shanmugam,Balamurugan, Rengarajan
, p. 333 - 351 (2020/12/22)
Herein, a facile diversity-oriented approach to access functionalized benzo[a]fluorenes, benzo[b]fluorenones, and naphthyl ketones has been demonstrated via site-selective intramolecular cyclization of aryl-fused 1,6-diyn-3-ones. Synthesis of benzo[a]fluorenes and naphthyl ketones has been achieved selectively using TfOH and AgBF4, respectively, via in situ-formed acetals. Aryl-fused 1,6-diyn-3-ones undergo triflic acid-mediated intramolecular cyclization, leading to benzo[b]fluorenone derivatives via a radical intermediate as supported by EPR studies. Kinetic studies of these transformations have also been performed by UV-visible spectroscopic analysis to shed light on the reaction profile.
Base-Catalyzed Cyclization of 1,6-Diynyl Carboxylates Involving Propargyl-Allenyl Isomerization: Efficient Synthesis of Benzo[b]fluorene and Its Analogues
Sun, Ning,Xie, Xin,Wang, Gaonan,Chen, Haoyi,Liu, Yuanhong
supporting information, p. 1394 - 1401 (2017/04/21)
An efficient protocol for the synthesis of benzo[b]fluorenes via base-catalyzed cyclization of 1,6-diynyl carbonates, esters or ethers has been developed. The reaction likely proceeds via base-induced propargyl-allenyl isomerization followed by Schmittel-type cyclization. Heterocycle-fused fluorenes such as thiophene- or pyridine-fused substrates could also be conveniently constructed by this method. The synthetic utility of this reaction was demonstrated by the preparation of up to seven-ring fused polycyclic aromatic hydrocarbons. (Figure presented.).
Gold-catalyzed cascade friedel-crafts/furan-yne cyclization/heteroenyne metathesis for the highly efficient construction of phenanthrene derivatives
Chen, Yifeng,Li, Guijie,Liu, Yuanhong
supporting information; experimental part, p. 392 - 400 (2011/04/22)
A rapid access to highly substituted phenanthrenyl ketones through gold-catalyzed cyclization of 1,6-diyn-4-en-3-ols with furans has been developed. Gold catalysts are effective to catalyze three cascade processes involving Friedel-Crafts/furan-yne cyclization/heteroenyne metathesis through C-O bond and alkyne activation. This method offers several advantages such as high selectivities and easily accessible starting materials.
