6448-90-4Relevant academic research and scientific papers
COMPOUNDS AND METHODS OF TREATING RNA-MEDIATED DISEASES
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Sheet 87/122, (2017/12/27)
The present invention provides compounds, compositions thereof, and methods of using the same.
1,3-bicyclo[1.1.1]pentanediyl: The shortest rigid linear connector of phenylated photochromic units and a 1,5-dimethoxy-9,10-di(phenylethynyl) anthracene fluorophore
De Meijere, Armin,Ligang, Zhao,Belov, Vladimir N.,Bossi, Mariano,Noltemeyer, Matthias,Hell, Stefan W.
, p. 2503 - 2516 (2008/04/01)
An excess of bis-1,3-(4-iodophenyl)bicyclo[1.1.1]pentane, prepared in 63% yield by iodination of 1.3-diphenylbicyclo[1.1.1]pentane, was selectively mono-coupled with 9-ethynyl-1,5-dimethoxy-10-phenylethynylanthracene (26), and subsequently with the zinc derivatives of 1-(2-methyl/methoxy-4-methyl-5- phenylthiophen-3-yl)-2-(2-methyl/methoxy-4-methylthiophen-3-yl) perfluorocyclopentenes (38-H-41-H). Regioselective synthesis of the 2-unsubslituted thiophenes 38-H-41-H required intermediate prepara tion of 2-trimethylsilyl-3,5-dimethyl-4-bromothiophene (37) or 2-trimethylsilyl-5- methoxy-3-methyl-4-bromothiophene (40). Protection of the α-position of the thiophene ring with a 2-trimethylsilyl group blocks the rearrangement of the 4-lithio derivatives into the corresponding 2-lithiated thiophenes. With the bicyclo[1.1.1]pentane frag ment linking the photochromic units 1-3 and 1,5-dimethoxy-9,10-di(phenylethynyl)anthracene as a fluorescent part, quantitative resonance energy transfer between the excited state of the fluorophore (donor) and the closed form of the photochromic units 1-3 (acceptors) was observed. The closed forms of the methoxy-substituted photochromic units 2 and 3 are less resistant to UV light (313 nm) than the closed form of 1.
Tandem intramolecular benzyne-furan cycloadditions. Total synthesis of vineomycinone B2 methyl ester
Sparks, Steven M.,Chen, Chi-Li,Martin, Stephen F.
, p. 8619 - 8635 (2008/02/08)
We have exploited tandem intramolecular benzyne-furan cycloadditions employing three different benzyne precursors to generate substituted bisoxabenzonorbornadienes in a single operation. The regiochemical outcomes in these Diels-Alder reactions were effectively controlled by using disposable silicon tethers to link the reacting benzyne and furan moieties. Two different methods for converting the intermediate bisoxabenzonorbornadienes to substituted anthrarufins were developed. The first tactic entails the initial cleavage of the silicon tethers followed by regioselective ring opening of the oxabicycloheptadienes and oxidation of the central ring giving the target anthrarufin, whereas the second features the regioselective ring opening of the oxabicycloheptadienes followed by protiodesilylation and oxidation. When the starting furans bear carbohydrate substitutents, this new methodology enables the rapid assembly of the glycosyl-substituted aromatic cores of complex C-aryl glycoside antibiotics from simple starting materials. The utility of this novel approach to anthrarufins and C-aryl glycosides is exemplified in a triply convergent synthesis of vineomycinone B2 methyl ester.
A New Convenient Synthesis of Alkoxyanthracenes from Alkoxy-9,10- anthraquinones
Lu, Lingang,Chen, Qiyin,Zhu, Xiaozhang,Chen, Chuanfeng
, p. 2464 - 2466 (2007/10/03)
Methoxy-9,10-anthraquinones with mono-, di- and tetraether groups at different positions 1a-h can be directly reduced to the corresponding methoxyanthracenes 3a-h in moderate to good yields by zinc in refluxing acetic acid. Under similar conditions, ethyl 1′-anthracenoxyacetate (3i) with the ester group unaffected and 1,8-oxybis(ethyleneoxyethyleneoxy)anthracene (5) were also conveniently synthesized in 65 and 70% yields, respectively.
N,N'-Diphenyl-1,4(5)-dimethoxyanthraquinone Diimines: "Butterfly" Inversion of Anthraquinone Diimines
Boone, Harold W.,Bruck, Michael A.,Bates, Robert B.,Padias, Anne Buyle,Hall, H. K.
, p. 5279 - 5283 (2007/10/02)
Model compounds for polyaromatic quinone imines were synthesized and characterized by variable-temperature 1H NMR spectroscopy and X-ray single crystal structure determination.N,N'-Diphenyl-1,4(5)-dimethoxyanthraquinone 9,10-diimines were synthesized by condensing 2 equiv of aniline with 1,5-dimethoxyanthraquinone (15DMAQ) and 1,4-dimethoxyanthraquinone (14DMAQ), respectively, in the presence of titanium tetrachloride and 1,4-diazabicyclooctane (DABCO).The X-ray single crystal structure determination of the diimine of 15DMAQ is reported.The condensation of aniline with anthraquinones results in a buckling of the anthraquinone ring system, giving it a "butterfly" conformation while the diimine of 15DMAQ has an anti configuration with the N-phenyl rings lying above the methoxy substituents.The diimine of 14DMAQ has a syn configuration, again with these N-phenyl rings lying above the methoxy substituents.The symmetrical structural butterfly conformations of the diimines allowed for the observation of a dynamic butterfly inversion by variable-temperature 1H NMR spectroscopy.The energy barriers for the butterfly inversion of N-phenyl 15DMAQ and 14DMAQ diimines are 9.5 kcal/mol.The implications of the crystal structure and molecular dynamics for the polymeric structures are discussed.
Asymmetric Diels-Alder Reactions of (S)-2-(p-Tolylsulfinyl)-1,4-naphthoquinones
Carreno, M. Carmen,Ruano, Jose L. Garcia,Urbano, Antonio
, p. 6870 - 6876 (2007/10/02)
The asymmetric Diels-Alder reactions of (S)-2-(p-tolylsulfinyl)-1,4-naphthoquinones 1a-c with cyclic dienes have been explored.The high ? facial diastereoselectivity observed can be reversed in the presence of ZnBr2.Evidence is presented to show that the regiochemical outcome of these reactions is controlled only by the sulfinyl group.The in situ cycloaddition/pyrolytic sulfoxide elimination starting from chiral 1a-c offers a convenient new route for the construction of enantiomerically pure 1,4-dihydro-9,10-anthraquinones (+)-10 and (+)-12a-c.
ESR Spectroscopic Detection of Intramolecular Interactions in Radical Cations of Poly(α-methoxy)triptycenes
Quast, Helmut,Fuchsbauer, Hans-Lothar
, p. 1016 - 1038 (2007/10/02)
-Cycloaddition of 1,4-benzoquinone to the di- and tetra(α-methoxy)anthracenes 11 yields the diketones 12 which undergo an acid-catalyzed rearrangement to the triptycene hydroquinones 13.Methylation of 13 affords the poly(α-methoxy)triptycenes 4.Aluminium chloride in nitromethane oxidizes the triptycenes 4 to the radical cations 4+* having one 1,4-dialkoxybenzene ring (4b+*, 4c+*, 4e+*) or two (4a+*) or three (4d+*), respectively, of such potential radical centers.The protons of the radical center give rise to hyperfine splittings which are very similar to those found in the ESR spectra of simple cis-1,4-dialkoxybenzene radical cations.The other aromatic protons, but not the bridgehead protons, exhibit a long range hyperfine coupling of 0.011 mT.Selective line broadening in the ESR spectrum of the radical cation 4a+* indicates that intramolecular electron transfer between the 1,4-dimethoxybenzene moieties occurs at a moderate rate.The deceleration of the exchange rate compared to the rate expected for a free radical cation is interpreted in terms of ion pairing.
Selective Dealkylation of Methoxyanthraquinones via Difluoro1,O9>boron Chelates: Synthesis of Hydroxymethoxyanthraquinones
Preston, Peter N.,Winwick, Thomas,Morley, John O.
, p. 1439 - 1441 (2007/10/02)
1,8-, 1,5- 1,2-, and 1,4-Dimethoxyanthraquinones have been treated with boron trifluoride-diethyl ether to give difluoro(anthraquinonato)boron chelates (1a-d) respectively. 1,4,5-Trimethoxyanthraquinone was similarly converted separately in benzene and toluene into the mono- (2) and bis-difluoroboron(3)-chelates respectively, and 2,2',4,4'-tetramethoxybenzophenone was converted by BF3*Et2O in toluene into the boron adduct (4).Treatment of these derivatives, (1a-d) and (2)-(4), with methanol gave the following uncomplexed derivatives in good yield respectively: 1-hydroxy-8-methoxyanthraquinone, 1-hydroxy-5-methoxyanthraquinone, 1-hydroxy-2-methoxyanthraquinone, 1-hydroxy-4-methoxyanthraquinone, 4-hydroxy-1,5-dimethoxyanthraquinone, 1,4-dihydroxy-5-methoxyanthraquinone, and 2-hydroxy-2',4,4'-trimethoxybenzophenone.
