219795-10-5Relevant academic research and scientific papers
Dications of fluorenylidenes. Electronic effects on the paratropicity/antiaromaticity of diphenylmethyl-substituted fluorenyl cations
Mills, Nancy S.,Malinky, Tiffany,Malandra, James L.,Burns, Ellen E.,Crossno, Peter
, p. 511 - 517 (1999)
Oxidation of para-substituted diphenylmethylidenefluorenes results in the formation of antiaromatic fluorenyl cations, as evidenced by the paratropic shift in the 1H NMR spectrum. The magnitude of the shift is affected by the nature of the remo
α-Bromoacrylic Acids as C1 Insertion Units for Palladium-Catalyzed Decarboxylative Synthesis of Diverse Dibenzofulvenes
Zhang, Minghao,Deng, Wenbo,Sun, Mingjie,Zhou, Liwei,Deng, Guobo,Liang, Yun,Yang, Yuan
, p. 5744 - 5749 (2021/08/18)
Herein α-bromoacrylic acids have been employed as C1 insertion units to achieve the palladium-catalyzed [4 + 1] annulation of 2-iodobiphenyls, which provides an efficient platform for the construction of diverse dibenzofulvenes. This protocol enables the formation of double C(aryl)-C(vinyl) bonds via a C(vinyl)-Br bond cleavage and decarboxylation. It is particularly noteworthy that the method features a broad substrate scope, and various interesting frameworks, such as bridged ring, fused (hetero)aromatic ring, and divinylbenzene, can be successfully incorporated into the products.
Ligand-Free Ru-Catalyzed Direct sp3 C-H Alkylation of Fluorene Using Alcohols
Shaikh, Moseen A.,Agalave, Sandip G.,Ubale, Akash S.,Gnanaprakasam, Boopathy
, p. 2277 - 2290 (2020/02/04)
The sp3 C-H alkylation of 9H-fluorene using alcohol and a Ru catalyst via the borrowing hydrogen concept has been described. This reaction was catalyzed by the [Ru(p-cymene)Cl2]2 complex (3 mol %) and exhibited a broad reaction scope with different alcohols, allowing primary and secondary alcohols to be employed as nonhazardous and greener alkylating agents with the formation of environmentally benign water as a byproduct. A variety of 9H-fluorene underwent selective and exclusive mono-C9-alkylation with primary alcohols in good to excellent isolated yield (26 examples, 50-92% yield), whereas this reaction with secondary alcohols in the absence of any external oxidants furnished the tetrasubstituted alkene as the major product. Furthermore, a base-mediated C-H hydroxylation of the synthesized 9H-fluorene derivatives afforded 9H-hydroxy-functionalized quaternary fluorene derivatives in excellent yield.
Palladium catalyzed atom-economic synthesis of functionalized 9-(diarylmethylene)-9H-fluorenes using triarylbismuths in one-pot bis-coupling process
Rao, Maddali L.N.,Dasgupta, Priyabrata
supporting information; experimental part, p. 162 - 165 (2012/01/30)
An efficient palladium catalyzed atom-economic synthesis of functionalized 9-(diarylmethylene)-9H-fluorenes has been accomplished in one-pot bis-coupling process using triarylbismuths as organometallic reagents. These bis-couplings in 1 hour short reactio
A double Suzuki approach for synthesis of substituted diarylmethylidenefluorenes
Ramana,Kishore Reddy, Bonthu K.,Reddy, Challa Nageswara,Gonnade, Rajesh G.,Gurjar, Mukund K.
, p. 127 - 128 (2008/03/13)
A convenient synthesis of substituted diarylmethylidenefluorene derivatives, using a double Suzuki reaction, is reported. Georg Thieme Verlag Stuttgart.
Dications of fluorenylidenes. Relationship between electrochemical oxidation potentials and antiaromaticity in diphenyl-substituted fluorenyl cations
Mills, Nancy S.,Benish, Michele A.,Ybarra, Christie
, p. 2003 - 2012 (2007/10/03)
The antiaromaticity of a series of dications of p-substituted diphenylmethylidene fluorenes was explored using three criteria attributed to aromaticity/antiaromaticity. The relative stability of the dications (energetic criterion) was measured via the red
Substituent Effects on Electron Spin Distribution and Conformation of Radical Ions obtained from 9-Diphenylmethylenefluorenes
Franco, M. Luisa T. M. B.,Herold, Bernardo J.,Evans, Jeffrey C.,Rowlands, Christopher C.
, p. 443 - 450 (2007/10/02)
Nine new substituted 9-diphenylmethylenefluorenes were synthetized.The reductions of the unsubstituted hydrocarbon and eleven substituted derivatives were studied by cyclic voltammetry in dimethylformamide solution.E.s.r. and ENDOR spectra of the radical anions obtained by reduction with alkali metal in tetrahydrofuran were recorded.The electron spin distribution as obtained from experiment was compared with the results of Hueckel-McLachlan calculations.The conformations of the radical anions were determined from the spectra.The ratio of electron spin densities in the fluorene part of the alkene and in the diphenylmethylene group obeys a linear Hammett correlation.A similar study was performed for the radical cations of six of the twelve alkenes.
