21846-07-1Relevant academic research and scientific papers
KHMDS mediated synthesis of 9-arylfluorenes from dibenzothiophene dioxides and arylacetonitriles by tandem SNAr-decyanation-based arylation
Mylavarapu, Saketh,Yadav, Mamta,Bhanuchandra
supporting information, p. 7815 - 7819 (2018/11/21)
A straightforward KHMDS mediated synthetic route to 9-arylfluorenes from readily available starting materials has been developed. This reaction involves SNAr reactions of dioxide with arylacetonitriles, followed by decyanation reaction. The pro
Au-catalyzed biaryl coupling to generate 5- to 9-membered rings: Turnover-limiting reductive elimination versus π-complexation
Corrie, Tom J. A.,Ball, Liam T.,Russell, Christopher A.,Lloyd-Jones, Guy C.
supporting information, p. 245 - 254 (2017/05/29)
The intramolecular gold-catalyzed arylation of arenes by aryl-trimethylsilanes has been investigated from both mechanistic and preparative aspects. The reaction generates 5- to 9-membered rings, and of the 44 examples studied, 10 include a heteroatom (N, O). Tethering of the arene to the arylsilane provides not only a tool to probe the impact of the conformational flexibility of Ar-Au-Ar intermediates, via systematic modulation of the length of aryl-aryl linkage, but also the ability to arylate neutral and electron-poor arenes-substrates that do not react at all in the intermolecular process. Rendering the arylation intramolecular also results in phenomenologically simpler reaction kinetics, and overall these features have facilitated a detailed study of linear free energy relationships, kinetic isotope effects, and the first quantitative experimental data on the effects of aryl electron demand and conformational freedom on the rate of reductive elimination from diaryl-gold(III) species. The turnover-limiting step for the formation of a series of fluorene derivatives is sensitive to the reactivity of the arene and changes from reductive elimination to π-complexation for arenes bearing strongly electron-withdrawing substituents (σ > 0.43). Reductive elimination is accelerated by electron-donating substituents (ρ = -2.0) on one or both rings, with the individual σ-values being additive in nature. Longer and more flexible tethers between the two aryl rings result in faster reductive elimination from Ar-Au(X)-Ar and lead to the π-complexation of the arene by Ar-AuX2 becoming the turnover-limiting step.
Au-Catalyzed Biaryl Coupling to Generate 5- To 9-Membered Rings: Turnover-Limiting Reductive Elimination versus ?-Complexation
Ball, Liam T.,Corrie, Tom J. A.,Lloyd-Jones, Guy C.,Russell, Christopher A.
supporting information, p. 245 - 254 (2021/09/04)
The intramolecular gold-catalyzed arylation of arenes by aryl-trimethylsilanes has been investigated from both mechanistic and preparative aspects. The reaction generates 5- to 9-membered rings, and of the 44 examples studied, 10 include a heteroatom (N, O). Tethering of the arene to the arylsilane provides not only a tool to probe the impact of the conformational flexibility of Ar-Au-Ar intermediates, via systematic modulation of the length of aryl-aryl linkage, but also the ability to arylate neutral and electron-poor arenes - substrates that do not react at all in the intermolecular process. Rendering the arylation intramolecular also results in phenomenologically simpler reaction kinetics, and overall these features have facilitated a detailed study of linear free energy relationships, kinetic isotope effects, and the first quantitative experimental data on the effects of aryl electron demand and conformational freedom on the rate of reductive elimination from diaryl-gold(III) species. The turnover-limiting step for the formation of a series of fluorene derivatives is sensitive to the reactivity of the arene and changes from reductive elimination to ?-complexation for arenes bearing strongly electron-withdrawing substituents (σ > 0.43). Reductive elimination is accelerated by electron-donating substituents (ρ = -2.0) on one or both rings, with the individual σ-values being additive in nature. Longer and more flexible tethers between the two aryl rings result in faster reductive elimination from Ar-Au(X)-Ar and lead to the ?-complexation of the arene by Ar-AuX2 becoming the turnover-limiting step.
Palladium-catalysed direct cross-coupling of secondary alkyllithium reagents
Vila, Carlos,Giannerini, Massimo,Hornillos, Valentin,Fananas-Mastral, Martin,Feringa, Ben L.
, p. 1361 - 1367 (2014/03/21)
Palladium-catalysed cross-coupling of secondary C(sp3) organometallic reagents has been a long-standing challenge in organic synthesis, due to the problems associated with undesired isomerisation or the formation of reduction products. Based on our recently developed catalytic C-C bond formation with organolithium reagents, herein we present a Pd-catalysed cross-coupling of secondary alkyllithium reagents with aryl and alkenyl bromides. The reaction proceeds at room temperature and on short timescales with high selectivity and yields. This methodology is also applicable to hindered aryl bromides, which are a major challenge in the field of metal catalysed cross-coupling reactions.
Highly efficient synthesis of polysubstituted fluorene via iron-catalyzed intramolecular Friedel-Crafts alkylation of biaryl alcohols
Sarkar, Soumen,Maiti, Sukhendu,Bera, Krishnendu,Jalal, Swapnadeep,Jana, Umasish
, p. 5544 - 5547 (2012/11/07)
An efficient and mild Fe(III)-catalyzed intramolecular Friedel-Crafts alkylation of biaryl methanol derivatives has been developed to achieve the substituted fluorene derivatives. The present reaction provides an excellent alternative to published methods
A general and efficient synthesis of substituted fluorenes and heterocycle-fused indenes containing thiophene or indole rings utilizing a Suzuki-Miyaura coupling and acid-catalyzed Friedel-Crafts reactions as key steps
Li, Guijie,Wang, Erjuan,Chen, Haoyi,Li, Hongfeng,Liu, Yuanhong,Wang, Peng George
, p. 9033 - 9043 (2008/12/22)
A general and efficient synthesis of fluorenes or heterocycle-fused indenes including 3-thia-cyclopenta[a]indenes, 9-thia-indeno[1,2-a]indenes, 5,6-dihydroindeno[2,1-b]indoles has been developed. This methodology is realized by a multistep protocol involv
Synthesis of 4-(4'-Chlorophenyl)-5-phenyl-1,2-dihydronaphthalene
Cosmo, Robert,Sternhell, Sever
, p. 1499 - 1509 (2007/10/02)
BF3-catalysed cyclization reactions of 1-(biphenyl-2'-yl)-1-(4"-chlorophenyl)but-3-en-1-ol yielded none of the desired title compound but only 9-(4'-chlorophenyl)-10-ethylphenanthrene and 9-allyl-9-(4'-chlorophenyl)fluorene by alternative cyclization path
Kinetic Hydrogen Isotope Effects in Intermolecular Hydride Transfer from Arylalkanes to 9-Arylfluoren-9-yl Cations
Bethell, Donald,Hare, Gerard J.,Kearney, Paul A.
, p. 684 - 691 (2007/10/02)
Rates of hydride-ion transfer to a series of 9-phenylfluoren-9-yl cations, substituted in the phenyl group, from triphenylmethane and 4,4'-dimethoxydiphenylmethane have been measured at 30 degC in trifluoroacetic acid solution containing 6percent v/v acet
