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1.
The reaction of coumarin with the title nitrile oxide gives a single regioisomer in high yield. This result is compared with the dipolarophilic behavior of cinnamic acid esters. 相似文献
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Krishnakumar V Xavier RJ 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(1-2):253-260
The solid phase mid FTIR and FT-Raman spectra of 3,5-dibromopyridine (3,5-DBP) and 3,5-dichloro-2,4,6-trifluoropyridine (3,5-DCTFP) have been recorded in the regions 4000-400 cm(-1) and 3500-100 cm(-1), respectively. The spectra were interpreted with the help of normal coordinate analysis (NCA) following full structure optimisation and force field calculations based on the density functional theory (DFT) using the standard B3LYP/6-31G( *) method and basis set combination. The results of the calculations are applied to stimulate infrared and Raman spectra of the title compounds which showed excellent agreement with the observed spectra. 相似文献
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Rodríguez N Cuenca A Ramírez de Arellano C Medio-Simón M Peine D Asensio G 《The Journal of organic chemistry》2004,69(23):8070-8076
Palladium-catalyzed cross-coupling reactions of racemic alpha-bromo sulfoxides with boronic acids are carried out in either aqueous or nonaqueous medium with formation of a new C sp(3)-C sp(2) bond. The arylation of chiral alpha-bromo sulfoxides occurs without racemization. The cross-coupling reaction is general and gives high yields with arylboronic acids substituted with either donor or acceptor groups but gives poor results with heteroarylboronic acids. The best yields are obtained using degassed solvents and CsF instead of aqueous base. The use of aqueous base and the presence of oxygen favor the homocoupling side reaction. 相似文献
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M. Schubert-Zsilavecz D. Gusterhuber W. Likussar G. Färber 《Monatshefte für Chemie / Chemical Monthly》1994,125(6-7):735-742
Summary Regio-, stereo- and siteselectivity of the cycloadditions of trimethylbenzonitrile oxide with 2H-3,4-Dihydro-1,4-benzoxazin-6(8aH)-ones have been investigated. The structures of the obtained products were elucidated by means of homonuclear NOE difference spectroscopy and HMQC and HMBC spectra. The structure of 6-Benzyl-9a-methoxy-3-mesityl-9b-methyl-7,8,9a,9b-tetrahydro-3aH-1,2-oxazolo-[4,5-h]1,4-benzoxazin-4(6H)-on5 was elucidated from a single crystal X-ray structure analysis at ambient temperature: C27H30N2O4, M=446.55g/mol, monoclinic, P21/c,a=10.372 (34) Å,b=11.908 (21) Å,c=20.040 (34) Å, =97.16 (17)°,V=2455.8 (1.9)Å3,Z=4,d
c=1.208g/cm3, =0.08mm–1,R=0.0546.Dedicated to Prof. Ott with best wishes for his 70th birthday 相似文献
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Franco Bellesia Franco Ghelfi Romano Grandi Ugo Maria Pagnoni Adriano Pinetti 《Journal of heterocyclic chemistry》1993,30(3):617-621
Pyrroles are powerful nucleophiles in the reaction with dialkyl sulfoxides and trimethylchlorosilane (TMCS) or trimethylbromosilane (TMBS), affording sulfonium salts or halo derivatives, generally in good yields. 相似文献
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A. M. Nazarov E. M. Chainikova P. V. Krupin S. L. Khursan I. A. Kalinichenko V. D. Komissarov 《Russian Chemical Bulletin》2000,49(9):1496-1500
The kinetics of the reactions of diphenylcarbonyl oxide with dimethyl, di-n-hexyl, diphenyl, dibenzyl, andn-hexylbenzyl sulfoxides in acetonitrile was studied by flash photolysis at 295 K. The oxidation of sulfoxide affords the corresponding
sulfone as the main reaction product, and diphenyl sulfide also forms in the case of Ph2SO. Solvent effect on the reaction kinetics and the composition of the reaction products was studied. The reaction mechanism
is discussed, which includes two parallel pathways: the nucleophilic attack of carbonyl oxide at the sulfur atom of sulfoxide
and the formation of the cyclic sulfurane intermediatevia the electrophilic 1,3-cycloaddition of Ph2COO at the S=O bond. The sulfurane undergoes fragmentationvia parallel channels to form sulfone or sulfide.
Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1504–1509, September, 2000. 相似文献
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Summary 5,5-Dichloro-2,4-pentadienal and 7,7-dichloro-2,4,6-heptatrienal readily condense with various ketones in presence of acid catalysts with formation of the corresponding polyenic ketones. 相似文献
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N. V. Fedorov M. V. Shevchenko A. V. Anisimov E. A. Viktorova 《Chemistry of Heterocyclic Compounds》1985,21(6):624-626
In the presence of acetic acid, allyl phenyl sulfoxide forms -acetoxyallyl phenyl sulfide and 2-acetoxymethyl-2,3-dihydrobenzothiophene; under the same conditions allyl 1-naphthyl sulfoxide gives 2-methyl-2,3-dihydronaphtho-[1,2-b] thiophenoxide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 747–749, June, 1985. 相似文献
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Antonio Massa Andrei V. MalkovPavel Ko?ovský Arrigo Scettri 《Tetrahedron letters》2003,44(38):7179-7181
Allylation of aldehydes with allyltrichlorosilane in the presence of sulfoxides is reported. The use of excess of (R)-methyl-p-tolylsulfoxide resulted in the formation of the corresponding homoallylic alcohols in good yields and moderate enantiomeric excesses. 相似文献
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Hélène Pellissier Author Vitae 《Tetrahedron》2006,62(24):5559-5601
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Shunsuke Kotani Shohei AokiMasaharu Sugiura Makoto Nakajima 《Tetrahedron letters》2011,52(22):2834-2836
Trichlorosilyl triflate, in the presence of a chiral Lewis base catalyst, provides an effective method for the enantioselective direct-type aldol reaction of aldehydes and ketones. A chiral Lewis base induces both the production and activation of trichlorosilyl enol ether, yielding an aldol product in good yield and with high diastereo- and enantioselectivities. 相似文献
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3,5-二氰基-2,4,6-三甲基吡啶在新型光电功能材料的合成中有重要的应用价值.本文在CCl4中光照1,4-二氢-3,5-二氰基-2,4,6-三甲基吡啶,高产率地合成了3,5-二氰基-2,4,6-三甲基吡啶. 相似文献
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The first example of enantioselective allylation of aldehydes with chiral allyl organolan-thanide reagents has been achieved in high chemical yield and moderate optical purity (up to 54% e.e.). 相似文献
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Palladium-catalyzed allylic alkylation of sulfenate anions, generated from beta-sulfinylesters by retro-Michael reaction, can take place under biphasic conditions. This new reaction provides a simple, mild, and efficient route to allyl sulfoxides in good yields. 相似文献
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V. V. Kastron A. F. Mishnev I. A. Skrastin'sh G. Ya. Duburs 《Chemistry of Heterocyclic Compounds》1995,31(8):974-979
The reaction of N-chlorosuccinimide with 2,6-dimethyl-3,5-dimethoxycarbonyl-4-(2-difluoromethoxyphenyl)-1,4-dihydropyridine (phoridone) has been studied. Depending on the amount of chlorinating agent, 3,4,5,6-tetrahydropyridines with different degrees of chlorination were obtained. The three-dimensional structure of 3,5-dimethoxycarbonyl-4-(2-difluoromethoxyphenyl)-2-methyl-6-chloromethylene-3, 5-dichloro-3,4,5,6-tetrahydropyridine has been studied.Latvian Institute of Organic Synthesis, Riga LV-1006. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1118–1123, August, 1995. Original article submitted July 28, 1995. 相似文献