56954-91-7Relevant academic research and scientific papers
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
Original synthesis of fluorenyl alcohol derivatives by reductive dehalogenation initiated by TDAE
Giuglio-Tonolo, Alain Gamal,Terme, Thierry,Vanelle, Patrice
, (2016/11/09)
We report here a novel and easy-to-handle reductive dehalogenation of 9-bromofluorene in the presence of arylaldehydes and dicarbonyl derivatives to give the corresponding fluorenyl alcohol derivatives and Darzens epoxides as by-products in tetrakis(dimethylamino)ethylene (TDAE) reaction conditions. The reaction is believed to proceed via two successive single electron transfers to generate the fluorenyl anion which was able to react with different electrophiles. A mechanistic study was conducted to understand the formation of the epoxide derivatives.
Photochemical Pinacol Rearrangements of Unsymmetrical Diols
Mladenova, Gabriela,Singh, Gurmit,Acton, Austin,Chen, Lie,Rinco, Olga,Johnston, Linda J.,Lee-Ruff, Edward
, p. 2017 - 2023 (2007/10/03)
The photochemical pinacol reaction of a series of nonsymmetrical 9-fluorenyl-substituted vic-diols was investigated and compared with their acid-catalyzed thermal reaction. Unlike the thermal reaction, the radiation-induced processes involve only fluorenyl cations, as is reflected in differences of product distribution between the two reactions. From the product studies, substituent migratory aptitudes are reversed in the photochemical process, suggesting that kinetic control takes place under neutral conditions unlike the acid-catalyzed thermal reactions. The presence of fluorenyl cation intermediates and their lifetimes were established by laser flash spectroscopy studies.
METHYLENE-CARBONYL CONDENSATIONS OF SOME CH ACIDS WITH ALDEHYDES UNDER THE CONDITIONS OF PHASE-TRANSFER CATALYSIS OR CATALYSIS BY THE FLUORIDE ION
Beletskaya, I.P.,Gulyukina, N.S.,Ali Ali, Muhamed,Solov'yanov, A.A.,Reutov, O.A.
, p. 657 - 661 (2007/10/02)
The condensation of a series of CH acids (fluorene, phenylacetonitrile, ethene) with aromatic aldehydes was realized in the aqueous sodium hydroxide-organic solvent-phase-transfer catayst system. 9-Substituted fluorenes do not enter into condensation under the indicated conditions.The condensation of fluorene, PhCH2CN, CH2(CN)2, and CH2(CN)COOEt with benzaldehyde and also of CH2(CN)COOEt with cyclohexanone was realized in the presence of tetrabutylammonium fluoride , deposited on silika gel.It was shown that the yield of the produt from crotonic condensation in the reaction of CH2(COOEt)2 with benzaldehyde is small, and this is due to the instability of PhCH=C(COOEt)2 under the reaction conditions.Sodiomalonic ester was condensed with benzaldehyde in the presence of titanium tetrachloride or aluminum chloride.
ACTIVATION DE LA LIAISON C-H FAIBLEMENT ACIDE PAR ADSORPTION SUR KF-Al2O3
Villemin, Didier,Ricard, Michele
, p. 1059 - 1060 (2007/10/02)
Condesation of poorly acidic carbon compounds (pka 18-30) with benzaldehyde was achieved by adsorption without solvent on KF-Al2O3.KF-Al2O3 appears as a stronger base than KF.
Studies of the Borderline between Concerted and Stepwise Mechanisms of Elimination : E1cB Elimination of Fluoren-9-ylmethyl Carboxylate Esters
O'Ferrall, Rory A. More,Larkin, Finbar,Walsh, Peter
, p. 1573 - 1580 (2007/10/02)
Rates of β-elimination of carboxylate leaving groups from fluoren-9-ylmethyl carboxylate esters in methanolic sodium methoxide at 25 deg C are reported.An E1cB mechanism with rate-determining formation of a carbanion intermediate is assigned on the basis of near identity of measured elimination rates and rates of carbanion formation predicted from a Taft correlation, and the similarity with elimination of 1-(1-acetoxy-1-methylethyl)indene for which the mechanism has been established by Ahlberg and Thibblin.Values of ρ=0.42 and βlg=0.27 measured for substituted benzoate leaving groups are a little larger than expected (ca. 0.24 and 0.18, respectively) and the discrepancy is tentatively ascribed to conformational enhancement of remote substituent effects, rather than to a contribution of E2 elimination.The effects of alkyl and aryl substitution α to the leaving group are discussed, especially in relation to the borderline between concerted and stepwise mechanisms.The measurements fail to confirm an earlier inference that the borderline shows a discontinuity in transition-state structure at the point of mechanistic change.
