- Nickel-Catalyzed C(sp3)-H Arylation of Diarylmethane Derivatives with Aryl Fluorides
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A novel nickel-catalyzed C(sp3)-H arylation with nonactivated aryl fluorides is reported. The use of 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes) as a ligand was found to be critical to the success of the reaction. This new method enables the synthesis of a wide range of triarylmethane derivatives.
- Li, Jie,Wu, Chen,Zhou, Bihui,Walsh, Patrick J.
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- Synthesis of 9-biarylfluorenes by one-pot, three-step reactions of N-tosylhydrazones, p-bromobenzeneboronic acid, and arylboronic acids
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A one-pot, three-step reaction of N-tosylhydrazones, p-bromobenzeneboronic acid, and arylboronic acids is established for the synthesis of 9-biarylfluorenes. Sequential formation of Csp3–Csp2 bond and Csp2–Csp2
- He, Jing,Zhang, Jie,Dai, Bin,Liu, Ping
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p. 268 - 273
(2019/07/15)
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- KHMDS mediated synthesis of 9-arylfluorenes from dibenzothiophene dioxides and arylacetonitriles by tandem SNAr-decyanation-based arylation
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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
- Mylavarapu, Saketh,Yadav, Mamta,Bhanuchandra
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supporting information
p. 7815 - 7819
(2018/11/21)
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- 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
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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
- Li, Guijie,Wang, Erjuan,Chen, Haoyi,Li, Hongfeng,Liu, Yuanhong,Wang, Peng George
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p. 9033 - 9043
(2008/12/22)
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- Flash photolysis study of a Friedel-Crafts alkylation. Reaction of the photogenerated 9-fluorenyl cation with aromatic compounds
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A combination of flash photolysis and product analysis is employed to investigate the reaction of aromatic compounds (ArH) with the 9-fluorenyl cation (Fl+) photogenerated from 9-fluorenol in 1,1,1,3,3,3-hexafluoroisopropyl alcohol (HFIP).The availability of the photochemical route to Fl+ means that the reaction of benzylic-type cation with ArH can be directly followed by flash photolysis.An additional feature with electron-rich ArH is that the cyclohexadienyl cation is observed to grow as Fl+ decays.Thus both cationic intermediates of a Friedel-Crafts alkylation are observed in the same experiment.The formation of the cyclohexadienyl cation is demonstrated to be reversible, or at least quasi-reversible, with the kinetic analysis furnishing absolute rate constants for the formation of this cation as well as for its loss of H+ and Fl+.Values of kH:kD for benzene:benzene and toluene:toluene are ca. 1.5 and demonstrate that Fl+ addition is at least partly reversible with these compounds as well.The Hammett ρ+ value obtained for a series of the less electron-rich ArH is -8, indicative of a transition state with considerable cyclohexadienyl cation character.Anisole shows a negative deviation from from Hammett correlation line, explained by the addition of Fl+ to ArH becoming encounter-controlled.This behaviour is dramatically illustrated in a comparison of data for Fl+ and Br2.For the less electron-rich ArH, rate constants for the two electrophiles are parallel.However, from m-xylene through pentamethylbenzene, the rate with Fl+ is unchanged, while the rate with Br2 increases over 1000-fold.The concept of encounter control with Fl+ is strongly supported by the absolute rate constants, which for the electron-rich ArH are all in the range 1-2 E9 dm3 mol-1 s-1, a magnitude typical of diffusion-controlled reactions.The electron-rich ArH also show no intermolecular selectivity since their reactions are encounter-controlled, but have a high intramolecular selectivity.It is suggested that a factor influencing the latter is the reversibility of formation of the cyclohexadienyl cation from the encounter complex.
- McClelland, Robert A.,Cozens, Frances L.,Li, Jianhui,Steenken, Steen
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p. 1531 - 1544
(2007/10/03)
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- Kinetics and Mechanism of the Reaction of 9-Arylfluoren-9-yl Cations with Polymethylbenzenes in Trifluoroacetic Acid Solution
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9-Arylfluoren-9-yl cations, ArFl+, generated from the alcohol in CF3CO2H solution, are reduced to ArFlH by the polymethylated aromatic hydrocarbons (Ar1CH3) hexamethylbenzene, pentamethylbenzene, 1,2,3,4-, 1,2,3,5-, and 1,2,4,5-tetra
- Bethell, Donald,Clare, Peter N.,Hare, Gerard J.
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p. 1889 - 1894
(2007/10/02)
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- Kinetic Hydrogen Isotope Effects in Intermolecular Hydride Transfer from Arylalkanes to 9-Arylfluoren-9-yl Cations
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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
- Bethell, Donald,Hare, Gerard J.,Kearney, Paul A.
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p. 684 - 691
(2007/10/02)
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