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971.
Sidhanath V. Bhosale Mohan B. Kalyankar Santosh V. Nalage Dattatry S. Bhosale Swati L. Pandhare Trupti V. Kotbagi 《合成通讯》2013,43(5):762-769
A simple one-pot synthesis has been developed for the synthesis of 2,4,5-trisubstituted imidazoles using an efficient and recyclable MoO3/SiO2 solid acid catalyst by condensation of benzil or benzoin, benzaldehyde, and ammonium acetate in acetonitrile as a solvent. Using this solid catalyst, the reactions could be carried out under mild reaction conditions with very good yield of imidazoles, up to 95%. This catalyst could be recycled very easily, which makes this methodology environmentally benign. 相似文献
972.
Giovanni Appendino Giancarlo Cravotto Giovanni Palmisano Rita Annunziata 《合成通讯》2013,43(18):3359-3371
In the presence of one-electron metal oxidants (CAN, MAH), 4-hydroxycoumarin (1) adds to alkenes to give 2,3-dihydro-4H-furo[3,2-c][1]benzopyran-4-ones. 相似文献
973.
Evans O. Onyango 《合成通讯》2013,43(20):2748-2755
The synthesis of a potential precursor 3 to demethoxyviridin (1b) is described. The centerpiece of this strategy was the conversion of the previously described dibromoolefin 6 to the masked alkyne β-hydroxyaldehyde 5 in a single step. Further elaboration then produced the alkyne oxazole 4, which on thermolysis, followed by in situ tautomerization and silylation, led directly to 3.
Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for full experimental and spectral details. 相似文献
974.
A sequential three-component reaction of aromatic aldehydes with Meldrum's acid and N-methyl indole in the presence of choline chloride/urea ionic liquid as green catalyst has been described. In this one-pot multicomponent reaction, a series of indole-3-propanamide derivatives were synthesized with good to excellent yields. This methodology shows several advantages including fast reaction, easy isolation, operational simplicity that make it a useful and attractive option for the library generation of indole-3-propanamides (5a–l) for drug discovery. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resources: Full experimental and spectral details.] 相似文献
975.
A mild and selective transition metal free protocol for the conversion of propargylic alcohols to cyclic and acyclic α,β-unsaturated enones via the Rupe rearrangement is reported. The method utilizes the Brønsted acidic ionic liquid [BMIM-SO3H][OTf] as catalyst and [BMIM][PF6] as solvent and offers the potential for recycling and reuse of the IL solvent. The feasibility to synthesize bicyclic fused cyclopentenone derivatives via a Rupe → Aldol → Nazarov sequence utilizing this protocol has also been demonstrated. 相似文献
976.
977.
978.
Chi Fang Ting Xiong Jie Hou Jing Wei Gu Mei Hu Sheng 《Journal of Dispersion Science and Technology》2013,34(4):604-610
Amidoxime (AO)/amine co-functionalized polypropylene fiber adsorbents were prepared. The all-polymeric structures were characterized by using Fourier transform infrared spectroscopy (FTIR), optical microscope, contact angle meter and electron spin resonance (ESR) analysis methods, confirming the grafting, modification, and amidoximation stages gravimetrically, spectroscopically, and visually. The properties for the removal of uranyl(VI) from aqueous solutions were investigated. For amidoxime (AO) fiber, high adsorption rate was observed within the first 30 minutes and the plateau value of 40.6% uranium loading (0.0812 mg/g) was reached at around 30 minutes. The adsorption equilibrium for AO/amine fiber was attained within 20 minutes, resulting in the adsorption of 92.6% uranium loading (0.185 mg/g). The percentage of adsorption increases with increasing pH value (2–6), reaches a maximum at pH 6.0 and then remains almost constant for AO/amine fiber, whereas reduces slightly for AO fiber. 相似文献
979.
The morphology of different ratio K/V catalysts supported on porous α‐alumina substrate was investigated by atomic force microscopy (AFM). Changes in the particle size distribution, pore size distribution were analyzed respectively using AFM software. In addition, their catalytic activities and compositions for carbon oxidation were studied by x‐ray diffraction (XRD), differential scanning calorimetry (DSC), and temperature‐programmed reactions (TPR). As a result, with the increase of K concentration, the mean particle size gradually increased and the mean pore size decreased. According to the catalytic activity studies, the catalytic activity of the KVO3 and K3V5O14 phases are more effective than KCl. 相似文献
980.
《Journal of Dispersion Science and Technology》2013,34(6):753-756
Mixed vesicles can be formed spontaneously from aqueous mixture of the double‐tailed anionic surfactant sodium bis(2‐ethylhexyl) sulfosuccinate (AOT) and the nonionic surfactant octylphenoxypolyethoxyethanol (Triton X‐100) under the inducement of salt, the formation mechanism of which should be attributed to the compression of salt on the electric bilayers of the head groups. The stability and the polydispersity of the vesicles are superior to single‐component AOT vesicles, which can be proved by the TEM image and visual observation. The vesicle region was presented in a pseudo‐ternary diagram of AOT/TX‐100/brine. The size of the vesicle was measured using dynamic light scattering. It is found that the vesicle size increases with the salinity but decreases with the content of TX‐100 in the mixture at the same salinity. Especially, the vesicle size is independent of the surfactant concentration at fixed salinity. 相似文献