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1.
Syntheses and photoisomerization of the new sulfone derivatives, 4,4‐di (p‐trifluoromethylphenyl)‐2,6‐diphenyl‐4H‐thiopyran‐1, 1‐dioxide and 4‐(p‐trifluoromethylphenyl)‐2,4,6‐triphenyl‐4H‐thiopyran‐1,1‐dioxide, have been investigated. The relative molar ratios of the photoproducts are compared with those of 2,4,4,6‐tetraphenyl‐4H‐thiopyran‐1,1‐dioxide as well as electron‐donating substituted 4‐methyl‐2,4,6‐triaryl‐4H‐thiopyran‐1,1‐dioxides as model compounds under identical experimental conditions using 1H NMR spectroscopy. The results observed are discussed on the basis of a triplet excited state di‐π‐methane rearrangement. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:557–561, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20455 相似文献
2.
E. E. Shul’ts G. N. Andreev M. M. Shakirov N. I. Komarova I. Yu. Bagryanskaya Yu. V. Gatilov G. A. Tolstikov 《Russian Journal of Organic Chemistry》2009,45(1):87-101
5-Isopropenyl-2,3-dihydrothiophene 1,1-dioxide reacted with 5-methylidenepyrimidine-2,4,6-triones and 5-methylidene-2-thioxopyrimidine-4,6-diones in the presence of chiral amines or amino acids with high regio- and stereoselectivity to give optically active derivatives of barbituric and thiobarbituric acids spirofused at the 5-position to 1-benzothiophene 1,1-dioxide fragment. The reaction of 5-isopropenyl-2,3-dihydrothiophene 1,1-dioxide with 5-(2-methoxybenzylidene)-2-thioxopyrimidine-4,6-dione (generated in situ from 2-methoxybenzaldehyde and thiobarbituric acid) in the presence of (?)-ephedrine or L-4-(tert-butyldimethylsiloxy) proline gave the corresponding 2-thioxospiro[1-benzothiophene-4,5′-pyrimidine]-4′,6′-dione 1,1-dioxide with an enantiomeric excess of 80%. 相似文献
3.
The reaction of “magic malonates” (bis-2,4,6-trichlorophenyl malonates, 1 ) with 5-aminotetrazole ( 2 ) in the presence of triethylamine yields the ammonium salts 3 . Upon treatment of 3 with strong acids compounds 4a-d were obtained as a mixture of isomeric tetrazolopyrimidines ( A ) and 2-azidopyrimidines ( B ). Reaction of 4d with bromine or sulfuryl chloride leads by ring opening and decarboxylation to the halogenated tetrazole derivatives 5 or 7 , respectively. The action of acetic anhydride in pyridine on 3d yields the zwitterionic tetra-mic acid derivative 10. 相似文献
4.
Hadjar Benmansour Graham Sandford Andrei S. Batsanov 《Journal of fluorine chemistry》2007,128(7):718-722
Palladium catalysed Suzuki cross-coupling reactions between 2,4,6-tribromo-3,5-difluoropyridine and a short series of aromatic boronic acid derivatives gave 4-bromo-3,5-difluoro-2,6-diphenylpyridine derivatives arising from displacement of bromine atoms attached to positions ortho to ring nitrogen or the corresponding triaryl systems depending on the reaction conditions. Consequently, the use of polybromofluoropyridine scaffolds for the synthesis of polyfunctional heteroaromatic derivatives is expanded further. 相似文献
5.
Cross-linked 4-vinylpyridine-styrene beads (PVPS) containing various amounts of pyridine rings were synthesized and reaction with methyliodide and peroxyacetic acid gave corresponding N-methylpyridinium salts and N-oxides with more than 92% of the pyridine rings being transformed. PVPS formed stable complexes with bromine and chlorine in the ratio 1:1, and when a higher amount of halogen was used, complexes with two molecules of halogen on each pyridine were formed. Similar complexes were also formed with PVPS-N-oxides in the presence of bromine and chlorine, while the reaction of PVPS-hydrohalide with bromine and chlorine resulted in hydrobromide perbromide and hydrochloride perchloride resins. The chemical activity of halo-substituted resins was tested in the reaction with 1,1-diphenylethylene. Chi or o-substituted resins are very stable, while bromo-substituted beads gave bromoalkene, dibromide, and alkoxybromide, depending on the structure of the reagent, solvent, and reaction temperature. 相似文献
6.
Thermal decomposition of 2,4,6-trimethylphenyl and (+)-2′-methoxy-1,1′-binaphthalen-2-yl (4-methylphenylsulfonyl)azidimidocarbonates
in the presence of norbornene, methyl acrylate, and camphene was studied. (+)-2′-Methoxy-1,1′-binaphthalen-2-yl (4-methylphenylsulfonyl)azidimidocarbonate
reacted with norbornene to give (+)-exo-2′-methoxy-1,1′-binaphthalen-2-yl N-(4-methylphenylsulfonyl)-3-azatricyclo-[3.2.1.02,4]octane-3-carboximidoate, while in the reaction with methyl acrylate a mixture of stereoisomeric methyl 1-[(2′-methoxy-1,1′-binaphthalen-2-yloxy)(4-methylphenylsulfonylimino)methyl]aziridine-2-carboxylates
was obtained. The reaction of 2,4,6-trimethylphenyl (4-methylphenylsulfonyl)azidimidocarbonate with (−)-camphene involved
insertion of intermediate nitrene into the exocyclic double bond with formation of 2,4,6-trimethylphenyl N-(3,3-dimethylbicyclo[2.2.1]heptan-2-ylidenemethyl)-N′-(4-methylphenylsulfonyl)-imidocarbamate as a 3: 1 mixture of E,E and E,Z diastereoisomers in good yield.
Published in Russian in Zhurnal Organicheskoi Khimii, 2008, Vol. 44, No. 10, pp. 1495–1500.
The text was submitted by the authors in English. 相似文献
7.
The title compounds, bearing an alkyl and/or bromine substituent on nitrogen, were synthesized. Unlike 5-bromo-6-methyluracil, 4-bromo-5-methyl-(2H)-1,2,6-thiadiazin-3-(6H)one 1,1-dioxides have the ability to act as a bromonium ion source. 相似文献
8.
Charles W. Jefford Grald Bernardinelli Ernest C. McGoran 《Helvetica chimica acta》1984,67(7):1952-1956
The reaction of 4-hydroperoxy-2,4,6-trimethylcyclohexa-2,5-dienone with acetaldehyde using trimethylsilyl trifluoromethanesulfonate as catalyst gives 1,1′-bis[(1,3,5-trimethyl-4-oxo-2,5-cyclohexadienyl) peroxy]diethyl ether ( 7 ) in 70% yield. The structure of this unusual acetal was determined by X-ray analysis. 相似文献
9.
Wadie Tadros Alfy Badie Sakla Sami Bassili Awad Nadia Fouad Abdul-Malik 《Helvetica chimica acta》1973,56(6):1829-1837
Xanthenyl and thioxanthenyl halides added readily to asymmetric diarylethylenes and their 2-halogeno-derivatives to give after dehydrohalogenation 1,1-diaryl-2-[xanthen(orthioxanthen)-9-yl]-ethylenes and 1,1-diaryl-2-halogeno-2-[xanthen(or thioxanthen)-9-yl]-ethylenes. The thioxanthenylethylenes were also obtained by another way. Reactions of these ethylenes with bromine, chlorine or sulfuryl chloride were influenced by the halogen and the nature of the p-substituent. Dehydrohalogenation of the 2-halogenoxanthenyl(or thioxanthenyl) ethylenes gave the corresponding 1,1-diaryl-2-[xanthen(or thioxanthen)-9-ylidene]-ethylenes. 相似文献
10.
Richard F. Smith Allen S. Craig Lorrene A. Buckley Richard R. Soelch 《Tetrahedron letters》1979,20(43):4193-4196
Thermolysis of 1,1-dimethyl-1-benzyl-2-(iminophenylmethyl)hydrazinium hydroxide inner salt gave dimethylamine, 2,4,6-triphenyl-s-triazine and 2,4,6-triphenyl-1,2-dihydro-s-triazine. 相似文献
11.
Quinolone Analogs 13: Synthesis of Novel 1,1′‐(2‐Methylenepropane‐1,3‐diyl)di(4‐quinolone‐3‐carboxylate) and Related Compounds
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Yoshihisa Kurasawa Kiminari Yoshida Naoki Yamazaki Eisuke Kaji Kenji Sasaki Yoshito Zamami Takatoshi Fujii Min Zhao Hideyuki Ito Haruhiko Fukaya 《Journal of heterocyclic chemistry》2014,51(6):1720-1726
The reaction of the 4‐hydroxyquinoline‐3‐carboxylate 6 with pentaerythritol tribromide gave the 1,1′‐(2‐methylenepropane‐1,3‐diyl)di(4‐quinolone‐3‐carboxylate) 11 , whose reaction with bromine afforded the 1,1′‐(2‐bromo‐2‐bromomethylpropane‐1,3‐diyl)di(4‐quinolone‐3‐carboxylate) 12 . Compound 12 was transformed into the (Z)‐1,1′‐(2‐acetoxymethylpropene‐1,3‐diyl)di(4‐quinolone‐3‐carboxylate) 13 or (E)‐1,1′‐[2‐(imidazol‐1‐ylmethyl)propene‐1,3‐diyl]di(4‐quinolone‐3‐carboxylate) 14 . Hydrolysis of the dimer (Z)‐ 13 or (E)‐ 14 with potassium hydroxide provided the (E)‐1,1′‐(2‐hydroxymethylpropene‐1,3‐diyl)di(4‐quinolone‐3‐carboxylic acid) 15 or (Z)‐1,1′‐[2‐(imidazol‐1‐ylmethyl)propene‐1,3‐diyl]di(4‐quinolone‐3‐carboxylic acid) 16 , respectively. The nuclear Overhauser effect (NOE) spectral data supported that those hydrolysis resulted in the geometrical conversion of (Z)‐ 13 into (E)‐ 15 or (E)‐ 14 into (Z)‐ 16 . 相似文献
12.
13.
Frank Luderer Helmut Reinke Hartmut Oehme 《Journal of organometallic chemistry》1996,510(1-2):181-188
Treatment of 2,4,6-triisopropylbenzaldehyde with tris(trimethylsilyl)silylmagnesium bromide (2) gives 2,4,6-triisopropylphenyl-tris(trimethylsilyl)silyl-methanol (3) in approximately 70% yield and E-3,4-bis(2,4,6-triisopropylphenyl)-1,1,2,2-tetrakis(trimethylsilyl)-1,2-disilacyclobutane (5) (15%). 5 is the [2 + 2] head-to-head cyclodimer of the transient 1,1-bis(trimethylsilyl)-2-(2,4,6-triisopropylphenyl)silene (4), formed by trimethylsilanolate elimination according to a Peterson mechanism from the magnesium alkoxide, derived from the alcohol 3. Deprotonation of 3 with McLi at low temperature in ether produces a complex mixture of products, the main constituents being the silene dimer 5 (10%) and bis(trimethylsilyl)-2,4,6-triisopropylbenzyl-trimethylsiloxysilane (10) (60%), which is formed by readdition of the eliminated lithiumtrimethylsilanolate at the Si=C bond of 4. The deprotonation of 3 with McMgBr or PhMgBr (activated by LiBr) in THF at room temperature results in the formation of the polysilane (Me3Si)3SiSi(SiMe3)2CH2(2,4,6-C6H2iPr3) (13). Its generation indicates that there exists an equilibrium between the magnesium alkoxide derived from the alcohol 3 on one side, and the magnesium silanide 2 and 2,4,6-triisopropylbenzaldehyde on the other side. Possible pathways of the formation of the compounds mentioned, as well as of further by-products, are discussed. The 1,2-disilacyclobutane 5 is characterized by an X-ray crystal structure analysis. 相似文献
14.
Minoru Suda 《Tetrahedron letters》1980,21(26):2555-2556
1,1-Difluoro-1-olefins react smoothly with electrophilic reagents such as bromine and acid chloride-Lewis acid at room temperature producing the addition products. 相似文献
15.
Arturo Gamonal Ruiz-Crespo Laura Galn-Fernndez Paloma Martínez-Martín Juan Carlos Rodríguez-Ubis 《Molecules (Basel, Switzerland)》2022,27(5)
A three-step synthetic route giving access to nonsymmetrical bisazolyl 2,4,6-trisubstituted pyridines with different substituents on the pyrazole, indazole, and pyridine heterocycles is described. From the readily available 4-bromo-2,6-difluoropyridine, both fluorine atoms allow for easy selective stepwise substitution, and the bromine atom provides easy access to additional functionalities through both Suzuki and Sonogashira Pd(0) cross-coupling reactions. These synthons represent optimal structures as building blocks in complexation and metalloorganic structures for the tuning of their chelating and photophysical properties. 相似文献
16.
Manfred Weidenbruch Andrea Pellmann Youlin Pan Siegfried Pohl Wolfgang SaakHeinrich Marsmann 《Journal of organometallic chemistry》1993,450(1-2):67-71
Treatment of chlorobis(2,4,6-triisopropylphenyl)silane (Ar2SiHCl) with lithium naphthalenide and subsequent addition of the chlorosilanes R2SiHCl (R = iPr, tBu, Mes) gives the unsymmetrical disilanes R2HSiSiHAr2 which are smoothly converted into the 1,2-dichlorodisilanes 8–10. The X-ray structure analysis of the 1,1-dimesityldisilane 10 reveals a staggered conformation with the chlorine atoms disposed in an anti orientation. Whilst the reductive chloride elimination from the 1,1-dialkyldichlorodisilanes 8 and 9 did not give the corresponding disilenes, the same reaction of 10 provided bright yellow crystals of 1,1-dimesityl-2,2-bis(2,4,6-triisopropylphenyl)disilene, the structure of which was confirmed by a complete NMR study. 相似文献
17.
Anat Bernstein Zeev Ronen Elena Levin Ludwik Halicz Faina Gelman 《Analytical and bioanalytical chemistry》2013,405(9):2923-2929
The increasing use of kinetic isotope effects for environmental studies has motivated the development of new compound-specific isotope analysis techniques for emerging pollutants. Recently, high-precision bromine isotope analysis in individual brominated organic compounds was proposed, by the coupling of gas chromatography to a multi-collector inductively coupled plasma mass spectrometer using strontium as an external spike for instrumental bias correction. The present study, for the first time, demonstrates an application of this technique for determining bromine kinetic isotope effects during biological reaction, focusing on the reductive debromination of brominated phenols under anaerobic conditions. Results show bromine isotope enrichment factors (ε) of ?0.76?±?0.08, ?0.46?±?0.19, and ?0.20?±?0.06?‰ for the debromination of 4-bromophenol, 2,4-dibromophenol, and 2,4,6-tribromophenol, respectively. These values are rather low, yet still high enough to be obtained with satisfying certainty. This further implies that the analytical method may be also appropriate for future environmental applications. 相似文献
18.
New R-sulfanyl-substituted polychlorobuta-1,3-dienes were synthesized by reactions of hexachloro-1,3-butadiene or 1,1,2,4,4-pentachlorobuta-1,3-diene with dimethylbenzenethiols, heptane-1-thiol, and 4-methyl-7-sulfanyl-2H-chromen-2-one. Some sulfides were oxidized to the corresponding sulfoxides and sulfones or brominated with bromine. Among the synthesized compounds, the coumarin derivative, 4-methyl-7-(1,2,3,4,4-pentachlorobuta-1,3-dien-1-ylsulfanyl)-2H-chromen-2-one showed fluorescence properties. 1,1′,1″-[3,4-Dichlorobuta-1,3-diene-1,1,4-triyltris(sulfanediyl)]tris(2,4-dimethylbenzene) reacted with potassium tert-butoxide in petroleum ether to afford a mixture of isomeric 1,1′,1″-[4-chlorobuta-1,2,3-triene-1,1.4-triyltris(sulfanediyl)]tris(2,4-dimethylbenzene) and 1,1′,1″-[2-chlorobut-1-en-3-yne-1,1,4-triyltris(sulfanediyl)]-tris(2,4-dimethylbenzene). The GC/MS method was found to be useful for the separation of some sulfanyl-substituted butadiene isomer mixtures. The synthesized compounds were characterized by elemental analyses, mass spectrometry, UV-Vis, IR, and NMR (1H, 13C) or fluorescence spectroscopy. 相似文献
19.
The reaction of phenyl substituted cyclopropanes phenylcyclopropane and 1,1-diphenylcyclopropane, phenyl substituted bicyclobutanes 1-phenylbicyclobutane, 1-methyl-3-phenylbicyclobutane, 1-methyl-2,2-diphenylbicyclobutane, as well as phenyl substituted spiropentanes phenylspiropentane and 1,1-diphenylspiropentane with lithium metal or lithium di-t-butylbiphenyl (LiDBB) was investigated. Under suitable reaction conditions and choice of solvent in all cases cleavage of the single bond next to the activating phenyl group was observed. The dilithiumorganic compounds thus obtained are sufficiently stable and can be trapped with electrophiles. Lithium hydride elimination is observed as follow-up reaction only in a few cases. The corresponding anions of the strained ring systems 1-lithio-2,2-diphenylcyclopropane, 1-lithio-3-phenylbicyclobutane, 1-lithio-3-methyl-2,2-diphenylbicyclobutane, and 1-lithio-4-phenylspiropentane, which can be obtained by lithium bromine exchange or by metalation of the unsubstituted carbocycle, do not show any cleavage upon reaction with lithium metal. 相似文献
20.
Lee JH Je J Schlautmana MA Carraway ER 《Chemical communications (Cambridge, England)》2003,(2):270-271
The maximum intensity, Imax, and time required to reach the maximum emission, taumax, for 1-aminopyrene monitored in 1,1'-oxalyldi-4-methylimidazole (OD4MI) chemiluminescence (CL) reactions are approximately 61 times higher and 16 times faster than their respective values for bis(2,4,6-trichlorophenyl)oxalate (TCPO) CL reactions in the presence of imidazole (ImH). 相似文献