104820-82-8Relevant articles and documents
Br?nsted acid-mediated intramolecular cyclization of biaryl triazenes for the synthesis of fluorenes and 9,10-dihydro-phenanthrenes
Xu, Lijun,Yang, Weijun,Zhang, Lili,Miao, Maozhong,Yang, Zhigen,Xu, Xin,Ren, Hongjun
, p. 9206 - 9221 (2014)
The efficient synthesis of fluorenes from biaryl triazenes is successfully developed. Up to 27 examples of biaryl triazenes are converted into their corresponding fluorene derivatives in the presence of CF3COOH (4.0 equiv). Mechanism research i
IRIDIUM COMPLEX COMPOUND, COMPOSITION CONTAINING THE COMPOUND AND SOLVENT, ORGANIC ELECTROLUMINESCENT ELEMENT CONTAINING THE COMPOUND, DISPLAY DEVICE, AND ILLUMINATION DEVICE
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Paragraph 0305; 0333; 0339, (2020/11/27)
Provided is an iridium complex compound represented by formula (1) below. [Ir is an iridium atom. C1 to C6 are carbon atoms. N1 and N2 are nitrogen atoms. R1 to R4 are each a hydrogen atom
Synthesis of methylene-bridge polyarenes through palladium-catalyzed activation of benzylic carbon-hydrogen bond
Hsiao, Chien-Chi,Lin, Yi-Kuan,Liu, Chia-Ju,Wu, Tsun-Cheng,Wu, Yao-Ting
experimental part, p. 3267 - 3274 (2011/02/23)
In the presence of palladium(II) acetate [Pd(OAc)2] and an N-heterocyclic carbene (NHC) ligand, fluorene derivatives can be generated in good to excellent yields from 2-halo-2′-methylbiaryls through the benzylic C-H bond activation (14 examples; 81-97% yields). The scope and limitations of this protocol have been examined. A wide range of functional groups, such as alkyl, alkoxy, ester, nitrile, and others, is able to tolerate the reaction conditions herein. The cyclization of an isotope-labelled biphenyl gave the corresponding product with a primary kinetic isotope effect (k H/kD=4.8:1), which indicates that the rate-determining step of this reaction is the activation of the benzylic C-H bond. Moreover, indenofluorenes were also accessed in excellent results from terphenyls (3 examples; 91-92% yields). The cascade reaction of 2,6-dichloro-2′- methylbiphenyl with diphenylacetylene produced 8,9-diphenyl-4H-cyclopenta[def] phenanthrene in 60% yield through the activation of an aryl and a benzylic C-H bond. Copyright
Aralkyl-tetrahydro-pyridines, their preparation and pharmaceutical compositions containing same
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Page/Page column 8, (2010/02/10)
The present invention relates to compounds of formula (I): in which X represents N or CH; R1 represents a hydrogen or halogen atom or a CF3 group; n is an integer from 1 to 5; A represents a partially saturated carbonaceous bi- or tr
Chemical Consequences of the Intramolecular Interaction between a Sulphur Atom and a Methoxycarbonyl Group in Fluorene Systems
Nakanishi, Waro,Kusuyama, Yoshiaki,Ikeda, Yoshitsugu,Oki, Michinori
, p. 799 - 804 (2007/10/02)
The intramolecular interaction between a sulphur atom and a methoxycarbonyl group was found to affect their chemical reactivity.The rates of C-S bond cleavage in methyl-9,9-bis(ethylthio)fluorene-x-carboxylate, where x is 1, 2, or 3, with sodium ethanethiolate show that the rate is minimal, though comparable with the others, when x=1, because of steric effects.In contrast, methyl 9-(ethylthio)fluorene-x-carboxylates, where x=1, 2, or 3, exhibit the maximum rate when x=1.The rates of ester exchange in the presence of toluene-p-sulphonic acid indicate that the reaction is accelerated by the presence of two ethylthio groups at the 9 position of methyl fluorene-1-carboxylate but no significant effect is detected if there is only one ethylthio group.The hydrolysis of the thioketal group in 9,9-bis(ethylthio)fluorene is also accelerated by the presence of a 1-methoxycarbonyl group.The implication of these results are discussed with the use of a model compound.
THE EFFECTS OF THE NEIGHBORING METHOXYCARBONYL GROUP AND SULFUR ATOM(S) IN THE CARBON-SULFUR BOND CLEAVAGE AND THE ESTER EXCHANGE IN FLUORENE SYSTEMS
Nakanishi, Waro,Nakanishi, Hitoshi,Yanagawa, Yuko,Ikeda, Yoshitsugu,Oki, Michinori
, p. 105 - 108 (2007/10/02)
9,9-bis(ethylthio)fluorene (1a) reacted with sodium ethanethiolate in methanol ro give 9-ethylthiofluorene and diethyl disulfide suggesting that a C-S bond cleavage occurs by attack of a nucleophile at sulfur if a leaving group is sufficiently stable.The pseudo-first-order rate constans for the reaction of 1a and methoxycarbonyl-substituted 9-ethylthiofluorenes have suggested that the methoxycarbonyl group at 1-position exerts through space interaction eith sulfur atoms(s).The rate constants for ester exchange in 1-methoxycarbonylfluorene and its derivatives have been discussed on the ground of neighboring sulfur participation.
