排序方式: 共有129条查询结果,搜索用时 15 毫秒
21.
A facile, efficient oxidative deblocking of aldoximes and ketoximes to their corresponding aldehydes and ketones have been achieved by using silica gel supported chromium trioxide. 相似文献
22.
Glenn H. Miller 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(8):1237-1253
Poly(dimethylbutadiene) popcorn polymer oxidizes readily in the presence of oxygen at room temperature. Quantitative data are presented for the production of the major volatile product, 2,5-hexanedione, as well as for the secondary products: water, acetic acid, and acetaldehyde. Three reaction mechanisms formerly proposed for polyisoprene oxidation are considered for their applicability to poly(dimethylbutadiene) popcorn oxidation. Of these, one that assumes the formation of a Bevilacquatype peroxyalkoxy radical followed by hydrogen abstraction to form an alcohol group, double bond migration, formation of a peroxide radical adjacent to the alcohol, then elimination of a hydroxy radical and scission, can explain the experimental data. 相似文献
23.
Catalyzed by ytterbium(III) triflate [Yb(OTf)3], β‐lactams were stereoselectively synthesized from imines and acetyl chlorides in ionic liquid under mild conditions. The ionic liquid and catalyst could be recycled and reused as opposed to traditional solvent–catalyst systems. 相似文献
24.
Adsorption studies of monosubstituted benzene molecules with various functional groups on doped lanthanum chromite/cyclohexane surface have been performed. The results from the adsorption study can be used in selecting appropriate anchoring groups on the dispersant. It was found that high amount of O relative lo La on the LaCrO3 surface correlated with high amounts of adsorbed benzoic acid. Increase in the La content relative to the O on the powder surface increased the amount of adsorbed benzylamine. The high amount of benzoic acid adsorbed on 20% Ca-doped lanthanum chromite powder (Al)lated well with good colloidal stability caused by a carboxylic acid containing dispersant. Rheology experiments showed that a low degree of agglomeration is obtained using only a small amount of the carboxylic acid containing dispersant (Hypermer LP1). Etectrophoretic mobility measurements in water of this powder coated with the LP1 dispersant indicated electrosteric stabilisation. 相似文献
25.
An inclusion complex formation using β‐cyclodextrin (β‐CD) as the host molecule and deltamethrin as guest molecule was a first step towards improvement in conventional insecticide formulations. β‐CD‐deltamethrin inclusion complex formation in the absence and presence of the nonionic myrisitic acid monoethanolamide (C14MEA)/anionic α‐olefin sulfonate C12‐C14 (AOS) mixed surfactant system was comparatively studied. The co‐evaporation method was used for complex formation, which was subsequently characterized by analytical methods such as FTIR and XRD techniques. Important physical properties such as solubility, dispersion stability, and wettability were also studied. 相似文献
26.
The interactions between β‐cyclodextrin (β‐CD) and the mixtures of cationic‐anionic surfactants in aqueous solution were investigated by surface tension and 1H NMR measurements. It was shown that the critical micelle concentration (cmc) increased linearly with the increase of β‐CD concentration. Furthermore, β‐CD formed 1∶1 inclusion complex with both cationic and anionic surfactants in the mixed surfactant systems, and no significant selective inclusion was observed. The thermodynamic parameters of the inclusion process of β‐CD to mixed cationic‐anionic surfactants were calculated by a numerical method based on the surface tension measurements, and it was found that the inclusion process was both enthalpy and entropy favorable. 相似文献
27.
《合成通讯》2013,43(14):2673-2680
Abstract An expeditious β‐polynitration of 5,10,15,20‐tetrakis(2′,6′‐dichlorophenyl)porphyrin, its Zn and Cu derivatives with montmorillonite K10‐HNO3 and montmorillonite K10‐Cu(NO3)2 (claycop) under mild conditions using microwave irradiation in 72–95% yields has been described. 相似文献
28.
Reaction of cyclic sulfates of vic-diols with magnesium iodide in acetonitrile produced the corresponding olefins in excellent isolated yields at room temperature. Cyclic sulfates of trans-diols gave trans-alkenes exclusively. Cyclic sulfates of cis-diols gave a mixture of cis- and trans- alkenes. However, the cyclic sulfate of cyclic cis-diol afforded the corresponding cis-alkene only. 相似文献
29.
A convenient and efficient procedure for the synthesis of β‐alkyl/arylsulfanyl carbonyl compounds has been developed by a simple one‐pot reaction of dialkyl/diaryl sulfides with α,β‐unsaturated aldehydes, ketones, carboxylic esters, and nitriles in presence of indium and trimethylsilyl chloride under sonication. 相似文献
30.
Catalyzed by samarium triiodide (SmI3), substitution of acyl with N‐acylbenzotriazoles for acetyl in acetoacetic esters and acetylacetone proceeds smoothly under neutral conditions in open air, affording the corresponding β‐keto esters and β‐diketones in good yields. 相似文献