共查询到20条相似文献,搜索用时 31 毫秒
1.
Ali Ramazani Bagher Mohammadi Nader Noshiranzadeh 《Phosphorus, sulfur, and silicon and the related elements》2013,188(4):767-771
Protonation of the highly reactive 1:1 intermediates produced in the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates by 2-hydroxy-3-methyl-2-cyclopenten-1-one leads to vinyltriphenylphosphonium salts, which undergo an intramolecular Wittig reaction to produce the corresponding cyclobutene derivatives. The cyclobutene derivatives are not isolable and undergo electrocyclic ring-opening reactions in CH 2 Cl 2 at room temperature to produce dialkyl ( E )-2-(2-methyl-5-oxo-1-cyclopentenyl)-2-butenedioates in moderate yields. 相似文献
2.
Ali Ramazani Abolfazl Momeni-Movahhed Farideh Gouranlou 《Phosphorus, sulfur, and silicon and the related elements》2013,188(4):903-907
Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates, by 1-hydroxy-2-acetonaphthone leads to vinyltriphenylphosphonium salts, which undergo aromatic electrophilic substitution reaction with conjugate base to produce dialkyl 2-(3-acetyl-4-hydroxy-1-naphthyl)-3-(triphenylphosphoranylidene) butanedioates. Silica gel was found to catalyze conversion of dialkyl 2-(3-acetyl-4-hydroxy-1-naphthyl)-3-(triphenylphosphoranylidene) butanedioates to dialkyl 2-(3-acetyl-4-hydroxy-1-naphthyl)-2-butenedioates in solvent-free conditions at 90°;C in fairly good yields. 相似文献
3.
《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2189-2192
Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates, by 1-hydroxy-2-acetonaphthone leads to vinyltriphenylphosphonium salts, which undergo aromatic electrophilic substitution reaction with conjugate base to produce dialkyl 2-(3-acetyl-4-hydroxy-1-naphthyl)-3-(triphenylphosphoranylidene) butanedioates. Microwave was found to catalyze conversion of dialkyl 2-(3-acetyl-4-hydroxy-1-naphthyl)-3-(triphenylphosphoranylidene) butanedioates to dialkyl 2-(3-acetyl-4-hydroxy-1-naphthyl)-2-butenedioates in the presence of silica gel powder in solvent-free conditions. 相似文献
4.
Ali Ramazani Ali Souldozi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6):1325-1328
Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates, by 1-hydroxynaphthalene leads to vinyltriphenylphosphonium salts, which undergo aromatic electrophilic substitution reaction with conjugate base to produce dialkyl 2-(1-hydroxy-2-naphthyl)-3-(triphenylphosphanylidene)butanedioates. Silica gel was found to catalyze conversion of dialkyl 2-(1-hydroxy-2-naphthyl)-3-(triphenylphosphanylidene)butanedioates to alkyl 2-oxo-2 H -benzo[ h ]chromene-4-carboxylates in solvent-free conditions at 80°;C in fairly good yields. 相似文献
5.
Ali Souldozi Ali Ramazani Nader Noshiranzadeh 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6):1271-1275
Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates, by 1-(2-hydroxy-1-naphtyl)-1-ethanone leads to vinyltriphenylphosphonium salts, which undergo a Michael addition reaction with a conjugate base to produce corresponding stabilized phosphorus ylides. Dipotassium hydrogen phosphate powder was found to catalyze the conversion of stabilized phosphorus ylides to dialkyl (E, Z)-2-(1-acetyl-2-naphthyl)-2-butenedioates under thermal and microwave conditions in a solventless system. 相似文献
6.
Ahmad Shaabani Ayoob Bazgir Mohammad Bagher Teimouri Hamid Reza Bijanzadeh 《Phosphorus, sulfur, and silicon and the related elements》2013,188(4):833-839
Protonation of reactive 1:1 intermediates produced in the reaction between triphenylphosphine and dialkyl acetylenedicarboxylate by 3-(1-hydroxyethylidene)-2,4-pentanedione leads to vinyl phosphonium salts, which undergo Michael addition with the conjugate base of CH-acid to produce the title compounds in high yield. 相似文献
7.
Protonation of the reactive intermediates produced in the reaction between tert-butyl isocyanide and dialkyl acetylenedicarboxylates by aromatic carboxylic acids leads to vinylnitrilium cations, which undergo nucleophilic reaction with conjugate bases of the carboxylic acids to produce dialkyl (E)-2-[(benzoyloxy)(tert-butylimino)methyl]-2-butenedioates and this intermediate rearranges to the dialkyl (E)-2-{[benzoyl(tert-butyl)amino]carbonyl}-2-butenedioate derivatives. 相似文献
8.
Ali Ramazani Ali Reza Kazemizadeh Bijan Ganjeie Ebrahim Ahmadi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2569-2572
Tiourea reacts with dialkyl acetylenedicarboxylates in solventless conditions to form 1:1 adducts, which undergo a cyclization reaction to produce alkyl Z-2-(2-amino-4-oxo-1,3-thiazol-5(4H)-yliden)acetates in fairly good yields. The stereochemistry of the ethyl Z-2-(2-amino-4-oxo-1,3-thiazol-5(4H)-yliden)acetate was established by the use of X-ray single crystal structure analysis. The reaction is completely stereoselective. 相似文献
9.
Ali Ramazani Ali Morsali Bijan Ganjeie Ali Reza Kazemizadeh Ebrahim Ahmadi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2439-2442
Abstract Selenourea reacts with dialkyl acetylenedicarboxylates in acetone to form 1:1 adducts, which undergo a cyclization reaction to produce alkyl Z-2-(2-amino-4-oxo-1,3-selenazol-5(4H)-yliden) acetates in fairly good yields. The reaction is completely stereoselective. 相似文献
10.
Ali Ramazani 《Phosphorus, sulfur, and silicon and the related elements》2013,188(2):536-541
Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates, by biphenyl-2,2′ -diol leads to vinyltriphenylphosphonium salts, which undergo a Michael addition reaction with a conjugate base to produce the corresponding stabilized phosphorus ylides. Magnesium oxide powder was found to catalyze the conversion of the stabilized phosphorus ylides to alkyl 6-(2-alkoxy-2-oxoethyl)dibenzo[d,f][1,3]dioxepine-6-carboxylates in solvent-free conditions under microwave (0.5 KW, 3 min) and thermal (90 °C, 60 min) conditions. 相似文献
11.
Ali Ramazani Ebrahim Ahmadi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):565-567
Magnesium hydrogen sulfate powder was found to catalyze stereoselective conversion of dialkyl 2-(imido-N-yl)-3-(triphenylphosphorany-lidene)butanedioates to electron-poor (Z)-N-vinylimides in solvent-free conditions at 95°C 1 h in high conversions. Microwave also was found to catalyze the same reactions in the presence of magnesium hydrogen sulfate powder in solvent-free conditions in 3 min. 相似文献
12.
Issa Yavari Mehdi Adib Manzarbanoo Esnaashari 《Monatshefte für Chemie / Chemical Monthly》2001,132(12):1557-1561
Summary. The reactive 1:1 intermediate produced in the reaction between dialkyl acetylenedicarboxylates and triphenylphosphine was
trapped by ethyl 3-(1,2-dihydroquinoline-2-ylidene)-pyruvate to yield the isomeric dialkyl 3-ethoxy-4-oxo-5-(2-(1H)-quinolinylidene)-2-cyclopentene-1,2-dicarboxylates and trialkyl 4-(2-quinolyl)-1-cyclobutene-1,2,3-tricarboxylates in nearly
4:1 ratio.
Received April 3, 2001. Accepted (revised) May 22, 2001 相似文献
13.
Ali Ramazani Issa Amini Abdolhossain Massoudi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2373-2376
The protonation of the highly reactive 1:1 intermediates, produced in the reaction of triphenylphosphine and dialkyl acetylenedicarboxylates, by 1,1-binaphthyl-2,2′-diol leads to vinyltriphenylphosphonium salts, which undergo a Michael addition reaction to produce the corresponding stabilized phosphonium ylides. Dipotassium hydrogen phosphate powder was found to catalyze the conversion of the stabilized phosphonium ylides to alkyl 2-(2-alkoxy-2-oxoethyl)dinaphtho[2,1-d:1,2-f][1,3]-dioxepin-2-carboxylates under solvent-free conditions using microwave (0.6 KW, 3 min) and thermal (100°C, 60 min) conditions. 相似文献
14.
2-(2- and 3-Pyridyl)anilines (1, 2), 2,2-dimethyl-N-[2-(2- and 3-pyridyl)phenyl]propanamides (3, 4), and 2-, 3- and 4-(2-methoxyphenyl)pyridines (7-9) are readily synthesized using cross-coupling reactions. Whereas the amines 1, 2 undergo side reactions, the corresponding amides 3, 4 are deprotonated with lithium 2,2,6,6-tetramethylpiperidide (LTMP): the compound 3 at C6' under in situ quenching, and the compound 4 at C4'. When the ether 7 is subjected to the same reagent, lithiation occurs at C6'. 相似文献
15.
Issa Yavari Mohammad M. Ghanbari Ashraf S. Shahvelayati Maryam Ghazvini 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2551-2557
Stable crystalline phosphorus ylides are obtained in excellent yields from the 1:1:1 addition reaction between 5,5-diarylthiohydantoins and dialkyl acetylenedicarboxylates in the presence of triphenylphosphine. These phosphoranes undergo a smooth intramolecular Wittig reaction followed by an electrocyclic ring opening to produce dialkyl 2-(2,5-dihydro-5,5-diaryl-2-thioxo-1H-imidazol-4-yl)but-2-enedioates in good yields. 相似文献
16.
Russian Journal of Organic Chemistry - The reactions of 2-cyano-3-oxobutanethioamide with ethyl 3-aryl-2-bromopropanoates and dialkyl acetylenedicarboxylates afforded a combinatorial library of new... 相似文献
17.
The transformation of ethyl 3-{[1-(alkoxycarbonyl)-2-(dimethylamino)ethenyl]amino}2-cyanoprop-2-enoates 2 to dialkyl 3-aminopyrrole-2,4-dicarboxylates 3 in good yields is described. 相似文献
18.
Ali Ramazani Nader Noshiranzadeh 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6):1321-1324
A facial one-pot stereoselective synthesis of dialkyl 3,3-diacetyl-3 a -hydroxy-8-oxo-2,3,3 a ,8-tetrahydrocyclopenta[ a ]indene-1,2-dicarboxylates in fairly high yields by the intermolecular Wittig reaction of dialkyl 2-(1-acetyl-2-oxopropyl)-3-(triphenylphosphoranylidene) succinates and ninhydrin in the presence of MgSO 4 in solvent-free conditions at 100°;C is reported. 相似文献
19.
Ali Ramazani 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1839-1844
Microwave catalyzed one-pot stereoselective synthesis of dialkyl 1,1-diacetyl-8 a -hydroxy-8-oxo-1,2,8,8 a -tetrahydrocyclopenta[ a ]indene-2,3-carboxylates in fairly high yields by the reaction of dialkyl 2-(1-acetyl-2-oxopropyl)-3-(triphenylphosphoranylidene) succinates and ninhydrin in the presence of MgSO 4 in solvent-free conditions. 相似文献
20.
5-(Trimethylstannyl)-2H-pyran-2-one (11) and 3-(trimethylstannyl)-2H-pyran-2-one (30), readily prepared from the corresponding bromo-2H-pyran-2-ones, undergo Pd(0)-catalyzed coupling reactions with a variety of enol triflates to give 5- and 3- substituted 2H-pyran-2-ones, respectively. This reaction is applicable to the enol triflates of 14beta-hydroxy-17-ketosteroids, and therefore may prove useful in convergent syntheses of lucibufagins and bufadienolides. 相似文献