10599-70-9Relevant articles and documents
Photochromism of rotation-hindered furylfulgides influenced by steric modifications
Struebe, Frank,Siewertsen, Ron,Soennichsen, Frank D.,Renth, Falk,Temps, Friedrich,Mattay, Jochen
, p. 1947 - 1955 (2011)
The syntheses of a bicyclic furylfulgide 14 and a (benzofuryl)fulgide 15 with increased steric constraints are described. Their photochromic behaviors were analyzed by means of UV/Vis spectroscopic measurements, X-ray crystallography, and NMR experiments, and the results were compared to those of the furyl(methyl)fulgide 12 and the furyl(isopropyl)fulgide 13. Compounds 13E and 14E exhibit large quantum yields of 0.57 and 0.53 for the coloration reaction (E) → (C) compared with 12E and 15E (0.23 and 0.17). After irradiation with 350 nm light, 13E and 14E are transformed into the closed (C) forms almost quantitatively, whereas 12E and 15E result in a photostationary state with mixtures of the (E), (Z), and (C) forms. The crystal structures obtained for 13E, 14E, and 15E show that the fulgides adopt cyclizable helical (P)-Eα conformations with no significant differences in atomic distances in the hexatriene unit. 2D- and temperature-dependent NMR experiments showed that the enantio- and diastereotopomerization processes were suppressed in a fulgide for the first time. Compound 14E populates only the E α conformational state. In contrast, 13E and 15E both exist in the cyclizable Eα and the non-cyclizable Eβ conformations in solution. Due to the annulated benzene ring, 15E exhibits a higher thermodynamic barrier than 13E, so the "belly roll" process was reduced for 15, but the (E) → (Z) isomerization could not be suppressed. The structural modification of 14 successfully suppressed the (E) → (Z) isomerization as well as the belly roll process. The way in which the isomerization reaction is suppressed by steric hindrance could not be fully elucidated by using these methods. Copyright
Microwave solvent-free synthesis of some bioactive 3-(2,5-Dimethylfuran-3-yl)-pyrazoline derivatives and their antimicrobial activity
Kulathooran,Vadivel,Dhamodaran,Selvakumar
, p. 1067 - 1073 (2016)
A series of some new 1-thiocarbamoyl-3-(2,5-dimethylfuran-3-yl)-5-(fluoro/trifluoromethylphenyl) -2-pyrazolines 4a-f have been synthesized by treating with various fluoro/trifluoromethyl substituted chalcones, thiosemicarbazide and potassium carbonate using conventional heating and solventfree microwave irradiation techniques. The easy work-up of the products, rapid reaction and mild conditions are noticeable features of this protocol. Synthesized compounds have been screened for their in vitro antimicrobial activity against six microbial strains. Among them, 1-Thiocarbamoyl-3-(2,5-dimethylfuran-3-yl)-5-(3-fluorophenyl)-2-pyrazoline 4b showed maximum zone of inhibition against all the tested microorganisms. Structural elucidation of the synthesized compounds were determined on the basis of various spectroscopic methods.
Photochromic Heterocyclic Fulgides. Part 2. Electrocyclic Reactions of (E)-α-2,5-Dimethyl-3-furylethylidene(alkyl-substituted methylene)succinic Anhydrides
Darcy, Paul J.,Heller, Harry G.,Strydom, Peter J.,Whittall, John
, p. 202 - 205 (1981)
The pale yellow title compounds undergo reversible photochemical conrotatory electrocyclic reactions to give in quantitative yields deep red 7,7a-dihydrobenzofuran-5,6-dicaroxylic anhydrides, which are stable at 100 deg C.These photochromic systems, which have high quantum yields for photocolouration, are highly resistant to photodegradation and retain their photochromic properties in a variety of solvents.
ALKYLATION OF β-DICARBONYL COMPOUNDS BY 1,2,3-TRIHALOPROPANES AS A METHOD FOR THE PREPARATION OF β-SUBSTITUTED FURANS
Akhmedov, Sh. T.,Sadykhov, N. S.,Ismailov, V. M.,Akhundova, M. A.,Sadovaya, N. K.,et al.
, p. 1291 - 1295 (1986)
Alkylation of β-dicarbonyl compounds by 1,2,3-trihalides leads to a readily separable mixture of mono- and dialkylation products, and under more rigorous conditions, to 3-substituted 2,4-dimethylfurans.A similar reaction with propargyl bromide leads to furans with a "normal" structure, namely, 2,5-dimethylfurans.
Novel dithienylethenes with extended π-systems: Synthesis by aldol condensation and photochromic properties
Altenhoener, Kai,Lamm, Jan-Hendrik,Mattay, Jochen
experimental part, p. 6033 - 6037 (2011/02/23)
A facile and stereoselective route to symmetric π-extended dithienylethene derivatives is described. The key step of this route is an aldol condensation of 1,2-bis(5-formyl-2-methylthiophen-3-yl)cyclopentene with a large variety of acyl compounds. All synthesized photoswitches can be reversibly converted into the closed form by irradiation with visible light. The photochromic properties of nine new dithienylethenes are discussed. A new synthetic pathway leading to π-extended dithienylethenes is presented. Nine new photoswitches are obtained in a facile and very stereoselective procedure and their photochromic properties are discussed.
