- Synthesis of spirocyclic diarylfluorenes by one-pot twofold SNAr reactions of diaryl sulfones with diarylmethanes
-
Treatment of dibenzothiophene dioxides with cyclic diarylmethanes in the presence of KN(SiMe3)2 results in the formation of fluorene-based spirocyclic tetraarylmethanes in a single operation. The transformation would proceed via an intermolecular SNAr reaction of the dioxides with cyclic diarylmethylpotassium followed by intramolecular SNAr cyclization. This straightforward strategy provides a wide range of spirocyclic diarylfluorenes including unusual ones that are otherwise difficult to synthesize.
- Bhanuchandra,Yorimitsu, Hideki,Osuka, Atsuhiro
-
supporting information
p. 384 - 387
(2016/02/19)
-
- Polar Diels-Alder reactions using electrophilic nitrobenzothiophenes. A combined experimental and DFT study
-
The reactions between 2- and 3-nitrobenzothiophenes with three dienes of different nucleophilicity, 1-methoxy-3-trimethylsilyloxy-1,3-butadiene, 1-trimethylsilyloxy-1,3-butadiene and isoprene developed in anhydrous benzene and alternative under microwave irradiation with molecular solvents or in free solvent conditions, respectively, for produce dibenzothiophenes permit to conclude that both nitroheterocycles act as electrophile with the cited dienes. In the cases of the dienes 1-methoxy-3-trimethylsilyloxy-1,3-butadiene and 1-trimethylsilyloxy-1,3-butadiene which posses major nucleophilicity the observed product is the normal cycloaddition one. However when the diene is isoprene the product with both electrophiles follow the hetero Diels-Alder way. These reactions are considered polar cycloaddition reactions and the yields are reasonables. Moreover the polar Diels-Alder reactions of nitrobenzothiophenes with electron rich dienes 1-trimethylsilyloxy-1,3-butadiene have been theoretically studied using DFT methods.
- Della Rosa, Claudia D.,Mancini, Pedro M.E.,Kneeteman, Maria N.,Lopez Baena, Anna F.,Suligoy, Melisa A.,Domingo, Luis R.
-
-
- Palladium-catalyzed hydroxylation of aryl and heteroaryl halides enabled by the use of a palladacycle precatalyst
-
A method for the hydroxylation of aryl and heteroaryl halides, promoted by a catalyst based on a biarylphosphine ligand tBuBrettPhos (L5) and its corresponding palladium precatalyst (1), is described. The reactions allow the cross-coupling of both potassium and cesium hydroxides with (hetero)aryl halides to afford a variety of phenols and hydroxylated heteroarenes in high to excellent yield.
- Cheung, Chi Wai,Buchwald, Stephen L.
-
p. 5351 - 5358
(2014/06/23)
-
- The interplay of conformation and photophysical properties in deep-blue fluorescent oligomers
-
We report the synthesis, X-ray crystal structures and photophysics of new donor-acceptor oligomers of fluorene (F) and dibenzothiophene-S,S-dioxide (S) with constrained dihedral angles in the backbone. The materials display bright deep-blue fluorescence and evidence is presented for a planarised intramolecular charge-transfer (PICT) state in the F-S systems.
- Li, Haiying,Batsanov, Andrei S.,Moss, Kathryn C.,Vaughan, Helen L.,Dias, Fernando B.,Kamtekar, Kiran T.,Bryce, Martin R.,Monkman, Andrew P.
-
supporting information; scheme or table
p. 4812 - 4814
(2010/08/20)
-
- Synthesis and photochromic behaviour under flash photolysis and continuous irradiation of novel 2H-chromenes derived from hydroxydibenzothiophenes
-
The synthesis and photochromic properties, under flash photolysis and continuous irradiation, of new 2,2-diphenyl-2H-1-benzopyrans including a dibenzothiophene nucleus are described. Under flash photolysis, all compounds exhibit photochromic behaviour in solution at room temperature, but under continuous irradiation the same was not perceived. Compared to reference compounds, a general bathochromic shift and the existence of two absorption bands in the Vis spectra of the open forms, leading to a boardening in the absorption range, is observed. The heteroannellation effects on the spectrokinetic parameters are variable and depend on the position and geometry of the fused benzothiophene moiety. The effect of electron-withdrawing substituents in C(6) of the 2H-1-benzopyran skeleton, with the benzothiophene nucleus fused at the 7,8 positions, are analyzed.
- Oliveira, M.Manuel,Moustrou, Corinne,Carvalho, Luis M,Silva, José A.C,Samat, André,Guglielmetti, Robert,Dubest, Roger,Aubard, Jean,Oliveira-Campos, Ana M.F
-
p. 1709 - 1718
(2007/10/03)
-
- Oxygenation reactions of various tricyclic fused aromatic compounds using Escherichia coli and Streptomyces lividans transformants carrying several arene dioxygenase genes.
-
Bioconversion (biotransformation) experiments on arenes (aromatic compounds), including various tricyclic fused aromatic compounds such as fluorene, dibenzofuran, dibenzothiophene, carbazole, acridene, and phenanthridine, were done using the cells of Escherichia coli transformants expressing several arene dioxygenase genes. E. coli carrying the phenanthrene dioxygenase (phdABCD) genes derived from the marine bacterium Nocardioides sp. strain KP7 converted all of these tricyclic aromatic compounds, while E. coli carrying the Pseudomonas putida F1 toluene dioxygenase (todC1C2BA) genes or the P. pseudoalcaligenes KF707 biphenyl dioxygenase (bphA1A2A3A4) genes was not able to convert these substrates. Surprisingly, E. coli carrying hybrid dioxygenase (todC1::bphA2A3A4) genes with a subunit substitution between the toluene and biphenyl dioxygenases was able to convert fluorene, dibenzofuran, and dibenzothiophene. The cells of a Streptomyces lividans transformant carrying the phenanthrene dioxygenase genes were also evaluated for bioconversion of various tricyclic fused aromatic compounds. The ability of this actinomycete in their conversion was similar to that of E. coli carrying the corresponding genes. Products converted from the aromatic compounds with these recombinant bacterial cells were purified by column chromatography on silica gel, and identified by their MS and 1H and 13C NMR analyses. Several products, e.g., 4-hydroxyfluorene converted from fluorene, and cis-1,2-dihydroxy-1,2-dihydrophenanthridine, cis-9,10-dihydroxy-9,10-dihydrophenanthridine, and 10-hydroxyphenanthridine, which were converted from phenanthridine, were novel compounds.
- Shindo,Ohnishi,Chun,Takahashi,Hayashi,Saito,Iguchi,Furukawa,Harayama,Horinouchi,Misawa
-
p. 2472 - 2481
(2007/10/03)
-
- Synthesis of Monoamino and Monohydroxydibenzothiophenes
-
The synthesis of the four monoaminodibenzothiophenes and the four monohydroxydibenzothiophenes is described.
- Kudo, Hirotaka,Castle, Raymond N.,Lee, Milton L.
-
p. 215 - 218
(2007/10/02)
-
- DIBENZOTHIOPHENE DERIVATIVES AS SERUM LIPID LOWERING AGENTS
-
A compound of the general formula and pharmaceutically acceptable salts thereof, in which formula R0 is H, F, CL, Br or OCH3; R1 and R2 are the same or different and selected from the group consisting of H and alkyl groups having 1-3 carbon atoms; R3 is H or an alkyl group having 1-3 carbon atoms; R0 and the side-chain containing the radicals R1, R2 and R3 being placed on the same or different benzene ring. Pharmaceutical preparations containing these compounds are useful in a method for lowering the serum lipid concentration in mammals, including man. These same preparations are also useful for the combined lowering of serum cholesterol and triglyceride concentrations
- -
-
-