共查询到20条相似文献,搜索用时 15 毫秒
1.
A four component one-pot procedure (4-MC) was developed to assemble 3-heteroarylpropionic acids from commercially available materials. This new methodology affords the title compounds in high yields and without the use of chromatography. [reaction: see text] 相似文献
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A three-component one-pot procedure (3-MCR) was developed to assemble the spiroisoxazoline nucleus from commercially available materials. This new methodology affords the title compounds in high yields and without the use of chromatography. 相似文献
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Two oxathiozolidine-S-oxide templates have been developed and used in a four-component coupling protocol for the synthesis of a wide range of chiral sulfinimines in high enantiomeric excesses. The templates can be synthesized from cheap commodity chemicals in three steps in high yields. Furthermore the template is easily recovered in high yields for recycling. 相似文献
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Bon RS van Vliet B Sprenkels NE Schmitz RF de Kanter FJ Stevens CV Swart M Bickelhaupt FM Groen MB Orru RV 《The Journal of organic chemistry》2005,70(9):3542-3553
[reaction: see text] A multicomponent reaction (MCR) between amines, aldehydes, and isocyanides bearing an acidic alpha-proton gives easy access to a diverse range of highly substituted 2-imidazolines. The limitations of the methodology seem to be determined by the reactivity of the isocyanide and by the steric bulk on the in situ generated imine rather than by the presence of additional functional groups on the imine. Less reactive isocyanides, for example p-nitrobenzyl isocyanide 25a, react successfully with amines and aldehydes, using a catalytic amount of silver(I) acetate. Some of the resulting p-nitrophenyl-substituted 2-imidazolines undergo air oxidation to the corresponding imidazoles. Differences in reactivity of the employed isocyanides are explained with use of DFT calculations. Difficult reactions with ketones instead of aldehydes as the oxo-compound in this MCR are promoted by silver(I) acetate as well. 相似文献
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We present a novel protocol for the efficient synthesis of fused benzimidazolo piperazines starting from a four-component Ugi-Smiles reaction and a subsequent three-step cascade involving an acid-catalyzed cyclization, an intramolecular reductive cyclization, and an oxidation. 相似文献
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A series of new poly-functionalized dihydroquinoline derivatives (26 examples) were synthesized via three-component reactions of aldehydes (1 equiv) and 1-arylethylidenemalononitriles (2 equiv) in ethylene glycol using NaOH as a base promoter under microwave irradiation. During these reaction processes, the domino construction of dihydroquinoline skeleton with concomitant formation of two new cycles was readily achieved in a one-pot operation and in an intermolecular manner. 相似文献
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Koveza Vladislav A. Kulakov Ivan V. Shulgau Zarina T. Seilkhanov Tulegen M. 《Chemistry of Heterocyclic Compounds》2018,54(12):1127-1130
Chemistry of Heterocyclic Compounds - Reaction of 2-nitroacetophenone, furfurol, β-dicarbonyl compounds, and ammonium acetate led to 3-substituted... 相似文献
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Vugts DJ Koningstein MM Schmitz RF de Kanter FJ Groen MB Orru RV 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(27):7178-7189
A broad range of differently substituted dihydropyrimidines and thiazines can be efficiently prepared by using a four-component reaction between phosphonates, nitriles, aldehydes, and iso(thio)cyanates. The scope and limitations of this multicomponent reaction are fully described. Variation of all four components has been investigated. The nitrile and aldehyde inputs can be varied extensively, but variation of the phosphonate input remains limited. An interesting rearrangement leading to phosphoramidates has been observed. Furthermore, the multicomponent reaction seems to be restricted to the use of isocyanates with strongly electron-withdrawing substituents, but an interesting additional exchange reaction under microwave conditions leads to dihydropyrimidines with less electron-withdrawing substituents at N3. In addition, a diastereoselective formation of dihydropyrimidines has been observed when using a chiral aldehyde as the input. Finally, by changing the isocyanate component to an isothiocyanate, thiazines are efficiently formed instead of the corresponding thio-dihydropyrimidines. 相似文献
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Multicomponent synthesis of mono and bis 4-substituted-1,4-dihydropyridines from aldehydes,dimedone and ammonium acetate in the presence of an efficient recyclable catalyst,L-proline,in high yield and short reaction time is reported. 相似文献
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Number of novel derivatives of dihydrotriazolo-and-tetrazolopyrimidines containing carboxamide group in position 6 were obtained
by multicomponent Biginelli-type reaction. The structures of all synthesized compounds were proved by NMR and MS spectral
methods. The method of three-component Biginelli-type reaction is well suited for the synthesis of new promising dihydroazolopyrimidines
providing a scaffold for screening of biological activity. 相似文献
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An efficient synthesis of 2-alkyl-3-furoic acids has been developed. Addition of the lithium dianion of 4-oxo-2-phenylthiobutanoic acid ethylene acetal to aldehydes followed by acid-catalyzed cyclization produces furan products in high yield. 相似文献
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Lovely Begum Jane L. Humphreys Pamela R. Russi Roger C. Whitehead 《Tetrahedron letters》2004,45(33):6249-6253
Exploitation of the dual dehydrating and fluorodeoxygenating properties of the dialkylaminosulfurtrifluorides has allowed access to the C3-fluorinated analogues of (−)-shikimic acid. 相似文献
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Gian Paolo Chiusoli Luciano Pallini Giuseppe Salerno 《Journal of organometallic chemistry》1982,238(4):C85-C86
A highly regioselective addition of dienes to 3-butenoic acids is reported. Rhodium(I) cationic complexes are exceedingly efficient catalysts. 相似文献
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The use of the enzyme 3-methylaspartase in the synthesis of L-aspartic acids containing 3-halogeno- or 3-alkyl- substituents, in the (S)-configuration, and also some of the corresponding C-3 deuteriated isotopomers is described. 相似文献
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