共查询到20条相似文献,搜索用时 31 毫秒
1.
Chen YZ Wang DH Chen B Zhong JJ Tung CH Wu LZ 《The Journal of organic chemistry》2012,77(16):6773-6777
Using a catalytic amount of platinum(II) terpyridyl complex 3, 3,4-diarylthiophenes (2a-f) could be synthesized from 3,4-diaryl-2,5-dihydrothiophenes (1a-f) under visible light (λ > 450 nm) irradiation in degassed CH(3)CN. Spectroscopic study and product analysis reveal that the reaction is initiated by photoinduced electron transfer from 3,4-diaryl-2,5-dihydrothiophenes to platinum(II) complex 3, leading to the formation of 3,4-diarylthiophenes. 相似文献
2.
Symmetric and nonsymmetric diarylethenes with a 2,5-dihydropyrrole bridging unit have been prepared, and the photochromic properties are investigated. Both symmetric and nonsymmetric diarylethenes with 2,5-dihydropyrrole bridging units undergo reversible ring-opening and ring-closing photoisomerization reactions in nonpolar solvents with UV/vis light, and some of them exhibit good fatigue resistance and no marked degradation detected after 10 cycles via an on/off switch. In polar solvents, however, photochromic diarylethenes with 2,5-dihydropyrrole bridging units produce 3,4-diarylpyrrole derivatives instead of the ring-closing isomer of diarylethenes with UV light irradiation. A class of N-substituted 3,4-diphenylethenes with 2,5-dihydropyrrole bridging units were prepared and used as templates to investigate the conversion reactions. The mechanism of photoconversion of 3,4-diaryl-2,5-dihydropyrroles to 3,4-diarylpyrroles was explored as well. 相似文献
3.
Greger JG Yoon-Miller SJ Bechtold NR Flewelling SA MacDonald JP Downey CR Cohen EA Pelkey ET 《The Journal of organic chemistry》2011,76(20):8203-8214
A regiocontrolled synthesis of unsymmetrical 3,4-diaryl-3-pyrrolin-2-ones has been achieved in three steps from 1,2-diaryl-1-nitroethenes with pyrrole-2-carboxamides (pyrrole Weinreb amides) serving as the key linchpin intermediates. Two different methods for the preparation of the requisite nitroalkenes were investigated: (1) modified Henry reaction between arylnitromethanes and arylimines; and (2) Suzuki-Miyaura cross-coupling reaction of 2-aryl-1-bromo-1-nitroethenes with arylboronic acids. Some difficulty was encountered in the preparation of arylnitromethanes, thus leading to the exploration of a cross-coupling strategy that proved more useful. A Barton-Zard pyrrole cyclocondensation reaction between 1,2-diaryl-1-nitroethenes and N-methoxy-N-methyl-2-isocyanoacetamide gave the corresponding pyrrole Weinreb amides, which were then converted into the desired 3-pyrrolin-2-ones in two steps. Overall, this method allowed for the construction of 3,4-diaryl-3-pyrrolin-2-ones with complete regiocontrol of the substituents with respect to the lactam carbonyl. The utility of this synthetic methodology was demonstrated by the preparation of eight unsymmetrical and symmetrical 3,4-diaryl-3-pyrrolin-2-ones including the N-H lactam analogue of the selective COX-II inhibitor, rofecoxib. 相似文献
4.
O. E. Nasakin A. N. Lyshchikov P. M. Lukin A. Kh. Bulai 《Chemistry of Heterocyclic Compounds》1995,31(1):35-39
It was shown that briefly boiling solutions of 2,5-diaryl-3,3,4,4-tetracyanopyrrolidines in DMF caused rearrangement into 5-aryl-2-(N-arylidenamino)-3,4-dicyanopyrroles, which are methylated with diazomethane both at the NH bond and at the carbon atom of the azomethine fragment.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 42–46, January, 1995. 相似文献
5.
O. E. Nasakin A. N. Lyshchikov P. M. Lukin A. Kh. Bulai V. A. Tafeenko 《Chemistry of Heterocyclic Compounds》1997,33(9):1065-1069
A second direction has been found in the thermal conversions of 2,5-diaryl-3,3,4,4-tetracyanopyrrolidines. When they are refluxed in DMF or DMSO in the presence of a base, rearrangement does not take place, but rather elimination of two molecules of hydrogen cyanide and the formation of 2,5-diaryl-3,4-dicyanopyrroles. It was shown that 2,6-diphenyl-4,5-dicyanopyrrolo[2,3-d]pyrimidine is formed when the basicity of the medium is within certain limits.I. N. Ul'yanov Chuvash State University, Cheboksary 428015. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1222–1227, September, 1997. 相似文献
6.
Yamaguchi S Endo T Uchida M Izumizawa T Furukawa K Tamao K 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(9):1683-1692
A series of 2,5-diaryl-3,4-diphenylsiloles, with various mono-substituted phenyl groups, extended pi-conjugated groups, and heteroaryl groups as aryl groups at the 2,5-positions, has been prepared by a one-pot synthesis from bis(phenylethynyl)silanes based on the intramolecular reductive cyclization followed by the palladium-catalyzed cross-coupling with aryl halides. Crystal structures and chemical reactivities toward the alkaline desilylation reactions have been studied on the 2,5-bis(p-mono-substituted phenyl)silole derivatives to elucidate the effects of the p-substituents. The UV-visible absorption and fluorescence spectra, and cyclic voltammetry of the 2,5-diarylsiloles have been systematically evaluated. Their photophysical properties as well as their electronic structures significantly depend on the nature of the 2,5-aryl groups. 相似文献
7.
A one-pot reaction for the preparation of 3,4-diaryl-2,6-piperidinediones through acid hydrolysis of the corresponding ethyl 3,4-diaryl-4-cyanobutyrates is described.
Ein neuer einfacher Syntheseweg für 3,4-Diaryl-2,6-piperidindione
Zusammenfassung Durch saure Hydrolyse der entsprechenden Ethyl-3,4-diaryl-4-cyanobutyrate wurden in einem Schritt (Eintopfreaktion) die 3,4-Diaryl-2,6-piperidindione dargestellt.相似文献
8.
Synthesis of 2,5-diaryl-4-halo-1,2,3-triazoles and comparative study of their fluorescent properties
Vladimir A. Motornov Andrey A. Tabolin Roman A. Novikov Nikolay E. Shepel Valentine G. Nenajdenko Sema L. Ioffe 《Tetrahedron》2018,74(28):3897-3903
A convenient method for arylation of mono- and disubstituted 1,2,3-triazoles by copper-catalyzed Chan-Lam coupling was developed. The method is applicable for the regioselective synthesis of fluorescent 4-halogen-substituted (Hal?=?F, Cl, Br) 2,5-diaryl-1,2,3-triazoles in high yields. Comparative study of their fluorescent properties revealed that 4-fluorosubstituted triazoles possess the highest quantum yield (up to 0.69) among halogenated triazoles possessing Cl and Br in the position 4. 相似文献
9.
Massenspektroskopische Untersuchungen an 2,5-Diaryl-1-(arylimino)-1λ4,2,5-thiadia-zolidin-3,4-dionen
Richard Neidlein Peter Leinberger Alfred Hotzel 《Journal of mass spectrometry : JMS》1977,12(10):628-630
The mass spectra of 2,5-diaryl-1-(arylimino)-1λ4,2,5-thiadiazolidin-3,4-diones have been examined. Some fragmentations are explained by rearrangement of the title compounds to 1,3-(diarylimino)-5-aryl-1λ4,2,5-thioxazolidin-4-ones and 1-oxo-2,5-diaryl-3-(arylimino)-1λ4,2,5-thiadiazolidin-4-ones. 相似文献
10.
O. E. Nasakin A. N. Lyshchikov P. M. Lukin V. A. Tafeenko A. Kh. Bulai 《Chemistry of Heterocyclic Compounds》1997,33(12):1450-1455
Feasibility has been demonstrated for the synthesis of pyrrolo[1,2-a]pyrimidines by the reaction of 2,5-diaryl-3,3,4,4-tetracyanopyrrolidines I with -dicarbonyl compounds, which was carried out by the rearrangement of I to give 2-(N-arylidenamino)-5-aryl-3,4-dicaynopyrroles II. A different pathway was found for the reaction of pyrroles II with -diketones and ethyl acetoacetate. The existence of a latento-enaminonitrile fragment in these compounds permits their conversion to pyrrolo[2,3-d]pyrimidines.I. N. Ul'yanov Chubash State University, 428015 Cheboksary, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1676–1681, December, 1997. 相似文献
11.
Masakazu Nishida Yoshio Hayakawa Masaki Matsui Katsuyoshi Shibata Hiroshige Muramatsu 《Journal of heterocyclic chemistry》1992,29(1):113-116
Diels-Alder reaction of 2,5-dialkyl-3,4-bis(trifluoromethyl)furan with hexafluoro-2-butyne gave 1,4-dialkyl-7-oxa-2,3,5,6-tetrakis(trifluoromethyl)bicyclohepta-2,5-diene. Irradiation (uv) of 1,4-diethyl-7-oxa-2,3,5,6-tetrakis(trifluoromethyl)bicyclohepta-2,5-diene afforded 1-ethyl-2,3,4,5-tetrakis(trifluoromethyl)-1,4-cyclopentadiene, ethyl 3-[l-ethyl-2,3,4,5-tetrakis(trifluoromethyl)-1,4-cyclopentadienyl] ketone, and 2,7-diethyl-3,4,5,6-tetrakis(trifluoromethyl)oxepin. 相似文献
12.
Direct irradiation of 5,5-diaryl-2,5-dihydrofurans results in a di-π-methane rearrangement to give 3-penten-1-one derivatives. Triplet sensitization leads to the formation of a 2-oxyabicyclo[2.1.0]pentane which is extremely sensitive to heat and oxygen. 相似文献
13.
Proton transfer in the lower excited singlet state has been examined for ortho-hydroxy derivatives of 2,5-diaryl-1,3-oxazole
and 2,5-diaryl-1,3,4-oxadiazole in polystyrene films, as this largely determines the spectral characteristics. There is found
to be a substantial reduction in the radiationless deactivation in the product from that reaction, namely the phototautomeric
form, which is the basic reason for the low quantum yield in fluorescence in liquid solutions. These changes are explained
from the viewpoint of a reduction in the probabilities of high-amplitude intramolecular motions in the excited phototautomeric
forms of these ortho-hydroxy derivatives in a polymer.
Chemical Research Institute, V. Karazin Kharkov National University, 4 pl. Svobody, Kharkov 310077, Ukraine. Translated from
Teoreticheskaya i éksperimental'naya Khimiya, Vol. 35, No. 6, pp. 357–361, November–December, 1999. 相似文献
14.
Electrochromism has been demonstrated by three novel electrochemically-reversible compounds and, which were synthesised by Pd catalysed cross-coupling of iodotrimethylTTF (6) and 2,6(7)-diiodoTTF (7) with the 2,5-diaryl-1,3,4-oxadiazole derivatives 1 and 2 containing terminal ethyne and butadiyne groups. 相似文献
15.
L. I. Belen'kii S. I. Luiksaar I. S. Poddubnyi M. M. Krayushkin 《Russian Chemical Bulletin》1998,47(11):2238-2245
The reactions of trichloromethylarenes with excess hydrazine hydrate in ethanol gives symmetrical 2,5-diaryl-1,3,4-oxadiazoles
in 68–96% yields. The reaction of 1,4-bis(trichloromethyl)benzene with acylhydrazines in an ethanol-pyridine mixture gives
the corresponding substituted or unsubstituted 1,4-phenylenebis-1,3,4-oxadiazoles in 35–51% yields. The mass spectra of 2,5-diaryl-1,3,4-oxadiazoles
and 1,4-phenylenebis-1,3,4-oxadiazoles were studied.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2309–2316, November, 1998. 相似文献
16.
I. B. Dzvinchuk A. M. Nesterenko M. O. Lozinskii 《Chemistry of Heterocyclic Compounds》2008,44(2):190-196
Treatment of 1,4-diaryl-2-(1H-benzimidazol-2-yl)butane-1,4-diones with hydrazine gives the previously unknown 2-(3,6-diaryl-2,5-dihydropyridazin-4-yl)-1H-benzimidazoles
which are aromatized by oxidation with nitrous acid to give 2-[3,6-diarylpyridazin-4-yl]-1H-benzimidazoles.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 252–259, February, 2008. 相似文献
17.
18.
A. V. Samet E. A. Sil’yanova V. I. Ushkarov M. N. Semenova V. V. Semenov 《Russian Chemical Bulletin》2018,67(5):858-865
The Barton–Zard reaction of nitro substituted stilbenes and chalcones with ethyl isocyanoacetate afforded 3,4-diaryl- and 4-acyl-3-arylpyrroles, respectively. 3-Arylpyrrole-2,4- dicarboxylates and 4-arylisoxazoline N-oxides were side reaction products. Antimitotic activity of target 3,4-disubstituted pyrroles was studied on a sea urchin embryo model. Pyrroles unsubstituted at positions 2 and 5 were the most active. The activity increased with the number of methoxy groups in the Ar substituent. 相似文献
19.
Bis(2,4-diaryl-3-thienyl) disulfide was isolated in the thermal decomposition of 2,5-diaryl-1,4-dithiin. The formation of the rearranged product as well as the kinetic data suggest strongly the valence isomerization of 2,5-diaryl-1,4-dithiin in the course of the decomposition. 相似文献
20.
Velanganni Paul Alex Raja 《Tetrahedron》2006,62(20):4892-4899
The five-component reaction of ethyl 2-[(2-oxopropyl)sulfanyl]acetate, aromatic aldehydes, and ammonium acetate affords two diastereomers of 5,7-diaryl-5,6,7,8-tetrahydro-1H-pyrido[3,4-b][1,4]thiazin-2(3H)-ones via a novel tandem Mannich-enamine-substitution sequence. Presumably, they are generated from ethyl 2-[(4-oxo-2,6-diaryl-3-piperidinyl)sulfanyl]acetates. During the formation of the trans-5,7-diaryl-5,6,7,8-tetrahydro-1H-pyrido[3,4-b][1,4]-thiazin-2(3H)-ones from ethyl 2-[(4-oxo-2,6-diaryl-3-piperidinyl)sulfanyl]acetates, the configuration at the carbon bearing an aryl group adjacent to the enamide CC double bond is inverted via ring opening and closure. When o-substituted benzaldehydes were employed in this reaction, 5,7-diaryl-5,6-dihydro-1H-pyrido[3,4-b][1,4]thiazin-2(3H)-ones were obtained via air oxidation, along with trans-5,7-diaryl-5,6,7,8-tetrahydro-1H-pyrido[3,4-b][1,4]-thiazin-2(3H)-ones. 相似文献