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991.
The one‐pot multicomponent reaction of alkyl isocyanide, alkylidene‐substituted Meldrum's acid, and arylcarboxylic acids affords new derivatives of iminofuranone in fair yields. The structure of the products was deduced from their spectroscopic data. Two equivalents of the respective isocyanides participate in this reaction. 相似文献
992.
Kalaivani Subramaniam Amit Das Dagmar Steinhauser Manfred Klüppel Gert Heinrich 《European Polymer Journal》2011,47(12):2234-2243
This paper focuses on the influence of ionic liquid on carbon nanotube based elastomeric composites. Multi-walled carbon nanotubes (MWCNTs) are modified using an ionic liquid at room temperature, 1-butyl 3-methyl imidazolium bis (trifluoromethylsulphonyl) imide (BMI) and modified MWCNTs exhibit physical (cation–π/π–π) interaction with BMI. The polychloroprene rubber (CR) composites are prepared using unmodified and BMI modified MWCNTs. The presence of BMI not only increases the alternating current (AC) electrical conductivity and polarisability of the composites but also improves the state of dispersion of the tubes as observed from dielectric spectroscopy and transmission electron microscopy respectively. In addition to the hydrodynamic reinforcement, the formation of improved filler–filler networks is reflected in the dynamic storage modulus (E′) for modified MWCNTs/CR composites in amplitude sweep measurement upon increasing the proportion of BMI. Hardness and mechanical properties are also studied for the composites as a function of BMI. 相似文献
993.
Koosam Mahendar A. V. S. Sarma P. Raghavaiah Mannepalli Lakshmi Kantam Kenneth J. Klabunde 《Helvetica chimica acta》2011,94(8):1533-1542
Aldol‐type reaction between electron deficient aldehydes and sulfonium salts to afford the corresponding β‐hydroxy α‐sulfanyl esters in moderate‐to‐good yields by using nanocrystalline MgO is described. The sulfanyl group is a useful group for further transformations in organic synthesis. Low Rf‐value isomer is anti‐configured as revealed by X‐ray diffraction study and consistent with the assignment of 1H‐NMR spectrum. 相似文献
994.
Roya Akbarzadeh Tayebeh Amanpour Peiman Mirzaei Ayoob Bazgir 《Helvetica chimica acta》2011,94(8):1527-1532
Pyrano‐pyrido‐quinoxaline derivatives were synthesized in good yields by a three‐component reaction of isocyanides, dialkyl acetylenedicarboxylates, and pyrido[1,2‐a]quinoxaline‐triones in DMF at 100°. 相似文献
995.
An efficient procedure for the synthesis of N‐alkyl‐2,5‐diaryl‐1,3‐dioxol‐4‐amines 3 via a one‐pot reaction of aromatic aldehydes 2 and alkyl isocyanides 1 at room temperature in good yields is described (Scheme 1, Table). 相似文献
996.
An efficient protocol for the one‐pot reaction of isatoic anhydride (=1,2‐dihydro‐4H‐3,1‐benzoxazine‐2,4‐dione), primary alkylamines, and heterocumulenes (isothiocyanates and isocyanates) in H2O catalyzed by magnetically recoverable Fe3O4 nanoparticles is described. 相似文献
997.
The ‘t‐amino effect’ of amino‐nitroso compounds was documented by preparing the (dialkylamino)‐nitroso pyrimidines 4 – 18 , and cyclising them under thermal conditions in high yields to the purine derivatives 19 – 32 . The reactivity of the amino‐nitroso‐pyrimidines, particularly of 17 derived from diethyl iminodiacetate, and of 19 , derived from 1‐phenylimidazolidine, correlates with the stability of the intermediate azomethine ylide. Thermolysis of the amino‐nitroso‐pyrimidines 34 – 37 , possessing dialkylamino substituents at C(4) and C(6), proceeded by protiodenitrosation, leading to 38 – 41 . 相似文献
998.
The [Cu(acac)2]‐catalyzed reactions of α,β‐unsaturated carboxamides with dimethyl diazomalonate yielded dihydrofuran derivatives by a 1,5‐electrocyclic reaction at C(β), and butadiene derivatives by carbene addition reaction at C(α) (Schemes 4 and 5; Table). Phenyl substituents at the N‐atom of the amides seem to be effective on the reaction pathways (Table). 相似文献
999.
Laleh Torkian Minoo Dabiri Peyman Salehi Morteza Bararjanian 《Helvetica chimica acta》2011,94(8):1416-1425
The 1‐{[(1H‐1,2,3‐Triazol‐4‐yl)methoxy]phenyl}‐1H‐pyrazolo[1,2‐b]phthalazine‐5,10‐dione derivatives 5 were synthesized by a simple and efficient method, i.e., by the four‐component, one‐pot condensation reaction of phthalohydrazide 4 , a (propargyloxy)benzaldehyde 1 , an active methylene compound 3 (malononitrile or ethyl cyanoacetate), and an azide 2 in the presence of Cu(OAc)2/sodium L ‐ascorbate as catalyst and 1‐methyl‐1H‐imidazolium trifluoroacetate ([Hmim](CF3COO)) as an ionic‐liquid medium in good to excellent yields (Scheme 1). 相似文献
1000.
Manganese(III) acetate catalyzed oxidative radical‐addition reactions of α‐dicarbonyl compounds such as methyl acetoacetate ( 6 ), acetylacetone ( 7 ), and dimedone ( 8 ) to the mixture of 1‐ and 2‐phenylcyclohepta‐1,3,5‐triene ( 4 and 5 ) were investigated (Scheme 1). The 1‐phenylcyclohepta‐1,3,5‐triene ( 4 ) formed mainly [2+3] and [4+3] dihydrofuran addition products derived from cycloheptatriene and [2+3] dihydrofuran addition products derived from the norcaradiene structure. The 2‐phenylcyclohepta‐1,3,5‐triene ( 5 ) formed mainly [6+3] dihydrofuran addition products derived from cycloheptatriene and [4+3] dihydrofuran addition products derived from the norcaradiene structure. The structures of isolated products were established by their spectroscopic data (IR, 1H‐ and 13C‐NMR, MS, and elemental analysis) and comparison with literature data. The formation mechanism of the products is discussed. 相似文献