共查询到20条相似文献,搜索用时 31 毫秒
1.
Bin Yin 《Tetrahedron》2010,66(34):6820-10631
Anodic fluorination of various N-acetyl-3-substituted indole derivatives was successfully carried out in Et4NF-4HF/MeCN to provide the corresponding trans-2,3-difluoro-2,3-dihydroindoles exclusively or selectively. Treatment of difluorinated products with a base provided monofluoroindole derivatives or monofluoroindoline derivative depending on the substituents at the 3-position. 相似文献
2.
Noriaki Moriyama Yoshihiro Matsumura Masami Kuriyama Osamu Onomura 《Tetrahedron: Asymmetry》2009,20(23):2677-2687
A new method using electrochemical oxidation and/or OsO4 oxidation has been used for the stereoselective synthesis of 2,3,6-trihydroxylated (5S)-piperidine derivatives. The electrochemical method was successively used for the conversion of N-protected piperidines to N-protected 1-methoxypiperidines and for the conversion of 2,3-didehydro-1-methoxypiperidine derivatives to 2,3-trans-1,2,3-triacetoxypiperidine derivatives. These triacetates were easily transformed into (2S,3S)-6-triacetoxy-(5S)-methylpiperidine and (2R,3R)-6-triacetoxy-(5S)-methylpiperidine. In addition, the 2,3-cis-dihydroxylation of 2,3-didehydro-1-methoxypiperidine derivatives with OsO4 afforded (2R,3S)-6-triacetoxy-(5S)-methylpiperidine and (2S,3R)-6-triacetoxy-(5S)-methylpiperidine. 相似文献
3.
J.S. Yadav B.V.S. ReddyG. Satheesh A. PrabhakarA.C. Kunwar 《Tetrahedron letters》2003,44(10):2221-2224
2-Methylindole and its N-substituted derivatives react smoothly with 2,3-dihydrofuran (DHF) in the presence of a catalytic amount of InCl3 under mild conditions to afford the corresponding 2-methyl-3-perhydrofuro[2,3-b]oxepin-4-yl-1H-indole derivatives in fairly good yields with high diastereoselectivity, while 3,4-dihydro-2H-pyran (DHP) affords exclusively 5,5-di(1H-3-indolyl)-1-pentanol derivatives in high yields under similar reaction conditions. 相似文献
4.
A. E. Shchekotikhin E. K. Shevtsova Yu. N. Luzikov V. A. Barachevskii V. F. Traven’ 《Russian Journal of Organic Chemistry》2008,44(6):855-862
Nucleophilic replacement of the hydroxy groups in ethyl 4,11-dihydroxy-2-methyl-5,10-dioxo-5,10-dihydroanthra[2,3-b]furan-3-carboxylate by chlorine upon treatment with phosphorus acid chlorides gave the corresponding 4(11)-chloro derivatives which were converted into photochromic ethyl 4(11)-phenoxy-2-methyl-5,10-dioxo-5,10-dihydroanthra[2,3-b]furan-3-carboxylates. Photoinduced decomposition of the latter leads to the formation of phenol and fluorescent hydroxyanthra[2,3-b]furandiones. 相似文献
5.
Yu. N. Oludina S. V. Bukharov A. R. Burilov R. G. Tagasheva V. V. Syakaev R. Z. Musin E. F. Akhmetova G. N. Nugumanova 《Russian Chemical Bulletin》2014,63(1):115-117
Addition of isatin to the exocyclic double bond of dimethyl (3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)methylphosphonate gave dimethyl (3,5-di-tert-butyl-4-hydroxyphenyl)(2,3-dioxo-2,3-dihydro-1H-indol-1-yl)methylphosphonate. Its subsequent functionalization in reactions with thiosemicarbazide and 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionohydrazide yielded isatin derivatives containing several pharmacophoric fragments. 相似文献
6.
The reaction of furan-2,3-diones with S-methylisothiosemicarbazide hydroiodide yielded novel 1,2,4- triazine-5(4H)-ones, and reaction of furan-2,3-diones with diaminomaleonitrile led to the formation of pyrazine-2,3-dicarbonitrile derivatives, and the hydrolysis of these products led to the formation of more new pyrazine-2,3-dicarbonitrile derivatives. These compounds are potential herbicides and pesticides. 相似文献
7.
Leila Moafi 《Tetrahedron letters》2010,51(48):6270-6274
The synthesis of 2-amino-4-cyano-4H-chromene derivatives as new HA 14-1 analogues by a simple and efficient method is reported. In addition, the reaction of 2-amino-2H-chromene-3-carbonitriles, salicylaldehydes and amines results in the formation of new chromeno[2,3-d]pyrimidine derivatives. 相似文献
8.
A convenient synthesis and structural characterization of (Z)- and (E)-trans-2,3-dihydro-2-methyl-3-(1,2,4-triazolyl)-4H-1-benzopyran-4-one oxime ethers has been achieved. By analysis of vicinal interproton coupling constants, it is believed that trans-2,3-dihydro-2-methyl-3-(1,2,4-triazolyl)-4H-1-benzopyran-4-ones which exist predominantly in the diequatorial half-chair or sofa conformation was found to exist predominantly in the diaxial orientation upon conversion to the corresponding oxime ether derivatives. 相似文献
9.
The reaction between 1,3-cyclohexanediones and chalcones (or their vinilogs) in the presence of 2.5 equiv of cerium(IV) ammonium nitrate afforded trans-2-arylcarbonyl-3-aryl (or styryl)-2,3,6,7-tetrahydrobenzofuran-4(5H)-ones in good to excellent yields and in high diastereoselectivities. The method was also extended to the preparation of derivatives of the 5,6-dihydro-2H-cyclopenta[b]furan-4(3H)-one system. The fused 2,3-dihydrofuran derivatives were transformed into 1-alkyl-2-acyl-3-aryl-6,7-dihydroindole-4(5H)-ones by 2,3-dehydrogenation followed by reaction with primary amines. The direct reaction of the tetrahydrobenzofuran-4(5H)-one compounds derived from dimedone with amines gave 1-alkyl-2-alkylimino-3-aryl-6,7-dihydroindole-4(5H)-ones, while starting materials derived from 1,3-cyclohexanedione underwent an unprecedented 2-deacylation reaction and gave 1-alkyl-3-aryl-6,7-dihydroindole-4(5H)-ones. 相似文献
10.
《Tetrahedron letters》2019,60(24):1614-1619
A novel protocol for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones from 2-aminobenzamides and aldehyde derivatives catalyzed by KOH/DMSO suspension has been developed. The present transition metal free methodology is operationally simple, scalable and varieties of 2,3-dihydroquinazolin-4(1H)-one derivatives were obtained in good to excellent yields in short reaction times. 相似文献
11.
Khosrow Jadidi 《Tetrahedron》2009,65(10):2005-43
A simple and efficient cyclocondensation reaction of 2,6-diaminopyrimidin-4(3H)-one and isatins for the synthesis of spiro[pyrimido[4,5-b]quinoline-5,5′-pyrrolo[2,3-d]pyrimidine] and spiro[indoline-pyrido[2,3-d:6,5-d′]dipyrimidine] derivatives is reported. 相似文献
12.
Esráa S. Abu-Sheaib Jalal A. Zahra Mustafa M. El-Abadelah Roland Boese 《Monatshefte für Chemie / Chemical Monthly》2008,139(9):1061-1066
Cyclocondensation reaction of ethyl 7,8-diamino-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylate with 1-methylisatin produced a separable mixture of the corresponding indolo[3,2-b]- and [2,3-b]pyrido[2,3-f]quinoxaline-3-carboxylates, of which the latter isomer predominates. On the other hand, interaction with 1H-isatin or 5-chloroisatin gave the respective indolo[2,3-b]pyrido[2,3-f]quinoxaline-3-carboxylates as the sole regiospecific products. The structures of these new pentacyclic derivatives are based on microanalytical, spectral (IR, MS, and NMR) and X-ray crystal structure data. 相似文献
13.
O. V. Shitikova N. A. Ivanova Z. R. Valiullina M. S. Miftakhov L. V. Spirikhin 《Russian Journal of Organic Chemistry》2007,43(6):812-816
1H NMR study showed the possibility for intramolecular hydrogen bonding in 5(4)-hydroxy derivatives of 2,3-O-isopropylidene-β-D-ribofuranose in CDCl3. The obtained data were used to interpret differences in the 1H NMR spectra of structurally related 5-halo-2,3-O-isopropylidene-D-ribofuranosides and four newly synthesized diastereoisomeric 5-bromo-5-deoxy-4-hydroxy-2,3-O-isopropylidene-D-ribofuranosides. 相似文献
14.
Sigitas Tumkevicius Jelena Dodonova Viktoras Masevicius Saulius Jursenas 《Tetrahedron letters》2010,51(30):3902-339
The palladium-catalyzed Suzuki-Miyaura reaction of 2,4-dichloropyrrolo[2,3-d]pyrimidine with aryl boronic acids has been studied. Pd(OAc)2/dicyclohexyl(2-biphenyl)phosphine/K3PO4 was found to be an efficient catalyst system to prepare 4-aryl-2-chloro- and 2,4-diarylpyrrolo[2,3-d]pyrimidines. Novel non-linear molecules consisting of a pyrrolo[2,3-d]pyrimidine core and aryl branches have been elucidated as blue light-emitters with fluorescence quantum yields ranging from 4% to 67% in THF solution. The impact of an electron-withdrawing t-BuOCO group attached to the pyrrole ring of pyrrolopyrimidine derivatives on optical properties is discussed. 相似文献
15.
Mahmoud Farouk Salman A. Alrokayan Ahamad Imran Khalid M. Abu-Salah Mohamed Ghazzali Khalid A. Al-Farhan Salem El-Gohary Mamdouh Adly 《Chemical Papers》2013,67(2):229-235
3-Substituted quinazoline-2,4(1H,3H)-dione and 2,3-di-substituted quinazolineone derivatives attract considerable interest due to their pharmacological properties. In this paper, we report the synthesis of N-substituted-3-nitrophthalimide derivatives II?CIII, the reactions of phthalimide III with amines, hydrazines, and amino acid derivatives to synthesise a small library of 3-substituted-5-nitroquinazoline-2,4(1H,3H)-diones IV?CXIV and 2,3-di-substituted-6-nitro-quinazolineones XVIII?CXIX. 相似文献
16.
Olga Ya. Shyyka Nazariy T. Pokhodylo Yurii I. Slyvka Evgeny A. Goreshnik Mykola D. Obushak 《Tetrahedron letters》2018,59(12):1112-1115
A distinction in the behaviour of several hydrazines as N-nucleophiles in the recently developed one-pot method for pyrimidine core annulation via 1H-tetrazole ring cleavage was examined. The product structures, 2,3-diamino- or hydrazino derivatives of thieno[3,2-d]pyrimidin-4(3H)-ones, thieno[2,3-d]pyrimidin-4(3H)-ones and [1]benzofuro[3,2-d]pyrimidin-4(3H)-one, were elucidated based on NMR and single crystal X-ray analysis. 相似文献
17.
The reactivity of 2,3-dehydroproline and 2,3-dehydropipecolic acid methyl ester derivatives with S-nucleophiles in the thio-Michael addition reaction has been explored. The addition of triphenylmethanethiol and subsequent trityl cleavage led to the corresponding cis- and trans-(±)-3-mercaptoproline and pipecolic acid derivatives in good yields. 相似文献
18.
Mykhaylo V. Vovk Andriy V. Bol’butAlexander N. Chernega 《Journal of fluorine chemistry》2002,116(2):97-101
1-Aryl-1-chloro-2,2,2-trifluoroethylisocyanates react with 3-alkoxyphenols to form N-(1-aryl-2,2,2-trifluoroethylidene)-O-(3-alkoxyphenyl)urethanes, which undergo intramolecular thermal cyclization into derivatives of 2-aryl-2-trifluoromethyl-2,3-dihydro-4H-benzo[e][1,3]oxazin-4-ones. 相似文献
19.
《Tetrahedron: Asymmetry》2006,17(12):1859-1862
Suspension cultured cells of Marchantia polymorpha have the potential to hydrogenate the C–C double bonds of 2-methyl- and 2,3-dimethylmaleimide derivatives to give enantiomerically pure (2R)-2-methyl- and (2R,3R)-2,3-dimethylsuccinimide derivatives, respectively. 相似文献
20.
A. V. Borisov Zh. V. Matsulevich V. K. Osmanov G. N. Borisova A. D. Samsonova A. O. Chizhov 《Russian Chemical Bulletin》2012,61(3):678-679
Cycloaddition of 1,3-benzothiazole-2-selenenyl chloride to alkenes leads to 2,3-dihydrobenzo[d][1,3]selenazolo[2,3-b][1,3]thiazolium-4 derivatives. 相似文献