2871-85-4Relevant academic research and scientific papers
Palladium-catalyzed coupling reaction of 2-iodobiphenyls with alkenyl bromides for the construction of 9-(diorganomethylidene)fluorenes
Zhao, Ya-Heng,Wang, Jian-Long,Zhou, Yun-Bing,Liu, Miao-Chang,Wu, Hua-Yue
supporting information, p. 8250 - 8253 (2021/10/12)
An atom economical protocol for the construction of 9-(diorganomethylidene)fluorenes through palladium-catalyzed coupling reactions of 2-iodobiphenyls with alkenyl bromides has been reported. The reaction proceeds through the C-H activation/oxidative addition/reduction elimination/intramolecular Heck coupling reaction to afford a series of 9-(diorganomethylidene)fluorenes with good yields. Control experiments demonstrate that a five-membered palladacycle acts as a key intermediate and β-H elimination serves as the rate-limiting step.
Synthesis of 9-Fluorenylidenes via Pd-Catalyzed C-H Vinylation with Vinyl Bromides
Yang, Shuai,Zhang, Yanghui
supporting information, p. 7746 - 7750 (2021/10/12)
A facile and efficient approach for the synthesis of 9-fluorenylidenes has been developed via the palladium-catalyzed cross-coupling of 2-iodobiphenyls and vinyl bromides. The reaction involves the C-H activation of 2-iodobiphenyls and dual C-C bond formations. A range of 9-fluorenylidene derivatives, including diphenyldibenzofulvenes, can be synthesized with the reaction.
An N-heterocyclic carbene-catalyzed switchable reaction of 9-(trimethylsilyl)fluorene and aldehydes: Chemoselective synthesis of dibenzofulvenes and fluorenyl alcohols
Ma, Yu-Chuan,Luo, Jin-Yun,Zhang, Shi-Chu,Lu, Shu-Hui,Du, Guang-Fen,He, Lin
supporting information, p. 3717 - 3721 (2021/05/04)
An N-heterocyclic carbene-catalyzed synthesis of dibenzofulvenes and fluorenyl alcohols was developed. In the presence of 10 mol% NHC (1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) and 4 ? molecular sieves, 9-(trimethylsilyl)fluorene undergoes an olef
Iron(III) nitrate-induced aerobic and catalytic oxidative cleavage of olefins
Amaya, Toru,Fujimoto, Hayato
, p. 2657 - 2660 (2018/06/04)
Microwave-assisted catalytic oxidative cleavage of olefins using Fe(NO3)3·9H2O under O2 is reported. This reaction system is particularly effective when 9-benzylidene-9H-fluorene derivatives are used as substrates even though they are tri- and tetra-substituted olefins.
Pd-Catalyzed Autotandem Reactions with N-Tosylhydrazones. Synthesis of Condensed Carbo- and Heterocycles by Formation of a C-C Single Bond and a C-C Double Bond on the Same Carbon Atom
Paraja, Miguel,Valdés, Carlos
, p. 2034 - 2037 (2017/04/27)
A new Pd-catalyzed autotandem reaction is introduced that consists of the cross-coupling of a benzyl bromide with a N-tosylhydrazone followed by an intramolecular Heck reaction with an aryl bromide. During the process, a single and a double C-C bond are formed on the same carbon atom. Two different arrangements for the reactive functional groups are possible, rendering great flexibility to the transformation. The same strategy led to 9-methylene-9H-fluorenes, 9-methylene-9H-xanthenes, 9-methylene-9,10-dihydroacridines, and also dihydropyrroloisoquinoline and dihydroindoloisoquinoline derivatives.
Three-component Pd/Cu-catalyzed cascade reactions of cyclic iodoniums, alkynes, and boronic acids: An approach to methylidenefluorenes
Zhu, Daqian,Wu, Yongcheng,Wu, Baojian,Luo, Bingling,Ganesan,Wu, Fu-Hai,Pi, Rongbiao,Huang, Peng,Wen, Shijun
supporting information, p. 2350 - 2353 (2014/05/20)
Linear diaryliodonium salts are widely used as arylating reagents for C-C and C-X bond formation. Meanwhile, synthetic applications of cyclic iodoniums are relatively rare although they offer the opportunity to set up reaction cascades. We demonstrate an atom and step economical three-component reaction involving cyclic diphenyleneiodoniums, alkynes, and boronic acids, resulting in the construction of methylidenefluorenes in a single operation. Our route enables facile access to both symmetrical and unsymmetrical methylidenefluorene derivatives, compounds that have attracted interest due to their optical properties.
Dications of benzylidenefluorene and diphenylmethylidene fluorene: The relationship between magnetic and energetic measures of antiaromaticity
Do, Catherine,Hatfield, Julianne,Patel, Shirali,Vasudevan,Tirla, Cornelia,Mills, Nancy S.
supporting information; experimental part, p. 181 - 187 (2011/03/19)
Oxidation of m- and p-substituted benzylidene fluorenes to antiaromatic dications was attempted by electrochemical and chemical means. Electrochemical oxidation to dications was successful for benzylidene fluorenes with p-methoxy, p-methyl, p-fluoro, and
A comparative study in oxidative free radical reactions between 9-benzylidene-9-h fluorene derivatives and β-dicarbony1 compounds in the presence of mn(oac) 3 and can
Demirhan, Hulya,Arslan, Mustafa,Zengin, Mustafa,Kucukislamoglu, Mustafa
scheme or table, p. 488 - 494 (2012/04/23)
The reactions of some 1,3-dicarbonyl compounds with 9-benzylidene-9-H- fluorene derivatives in the presence of manganese(III)acetate and ceric ammonium nitrate (CAN) were searched. 9-benzylidene-9-H-fluorene compounds form mainly [2+3] dipolar cycloadditi
Synthesis of fluorenes via the palladium-catalyzed 5-exo-dig annulation of o-alkynylbiaryls
Chernyak, Natalia,Gevorgyan, Vladimir
experimental part, p. 1101 - 1114 (2009/12/07)
The direct palladium-catalyzed intramolecular hydro arylation of o-alkynylbiaryls proceeded in a highly stereoselective manner producing fluorenes 2, the products of 5-exo-dig cyclization, in excellent yields. The cascade intermolecular arylation, incorpo
Exclusive 5-exo-dig hydroarylation of o-alkynyl biaryls proceeding via C-H activation pathway
Chernyak, Natalia,Gevorgyan, Vladimir
, p. 5636 - 5637 (2008/12/22)
The first example of the palladium-catalyzed exclusive 5-exo-dig hydroarylation of o-alkynyl biaryls has been demonstrated. In contrast to the reported earlier carbocyclizations proceeding via the Friedel-Crafts mechanism, this hydroarylation efficiently proceeds with electron-neutral and electron-deficient arenes, producing fluorene frameworks with defined stereochemistry of the double bond. On the basis of the high reactivity of electron-deficient arenes toward cyclization, high values of inter- and intramolecular kinetic isotope effects, and the exclusive cis-selectivity of cyclization, a mechanism involving a C-H activation motif has been proposed for this transformation. Copyright
