نتایج جستجو برای: functionalized piperidines
تعداد نتایج: 21966 فیلتر نتایج به سال:
Starting from nitroarenes, under hydrosilylation conditions, using a well-defined N-heterocyclic carbene iron(0) catalyst, (IMes)Fe(CO)4, the corresponding aniline derivatives were produced in 61–92% isolated yields. More impressively, selective synthesis of cyclic amines such as pyrrolidines, piperidines and azepanes conducted levulinic acid, 1,5- 1,6-keto acids, respectively. The sequential p...
in this work we synthesized of mesoporous silica nanoparticles and functionalized with 3-aminopropyltriethoxysilane to improve the loading and release of ibuprofen bonded to 3-aminopropyltriethoxysilane. sample were characterized by fourier transform infrared spectroscopy, scanning electron microscopy , x-ray diffraction, and ultraviolet-visible. the fourier transform infrared spectroscopy resu...
The Prins reaction was investigated using BF₃.OEt₂ as a Lewis acid. It has been recently demonstrated, that if BF₃.OEt₂ is used in stoichiometric amounts then these reactions generate fluorinated products where the BF₃.OEt₂ contributes fluoride ion to quench the intermediate carbocations. In this study oxa- and aza-Prins reactions for the synthesis of 4-fluoro-pyrans and -piperidines were inves...
An approach to 2,4,5-trisubstituted piperidines is reported, in which the key step is the Prins or carbonyl ene cyclisation of aldehydes of the type 1. Prins cyclisation catalysed by concentrated hydrochloric acid in CH(2)Cl(2) at -78 degrees C afforded good yields of two of the four possible diastereomeric piperidines, with the 4,5-cis product 7 predominating in a diastereomeric ratio of up to...
Highly optically enriched, protected, nitrogenated heterocycles with different ring sizes have been synthesized by a very efficient methodology consisting of the asymmetric transfer hydrogenation of N-(tert-butylsulfinyl)haloimines followed by treatment with a base to promote an intramolecular nucleophilic substitution process. N-protected aziridines, pyrrolidines, piperidines, and azepanes bea...
The poly(ethyleneimine)-functionalized silica has been developed successfully as an effective adsorbent for the adsorption removal of Cu(II) ions from electroplating wastewater. The influences of pH, contact time and initial concentration of Cu(II) ions on the adsorption capacity and the effect of adsorbent dosage on the removal efficiency of Cu(II) ions from electroplatin...
in this work, so3h-functionalizedphthalimide (sfp) as a so3h-containing solid acid is prepared by the reaction of phthalimide with chlorosulfonic acid, and characterized by ft-ir, 1h and 13c nmr, mass, tg, dtg, xrd and sem. then, it is utilized as a highly efficient, heterogeneous and green catalyst for the one-pot multi-component condensation of dimedone with arylaldehydes, β-ketoesters and am...
In this work we synthesized Nano hydroxyapatite (HAp) by Sol-gel method, Then we functionalized hydroxyapatite nanoparticle by use of 3-Aminopropyl trimethoxysilane (APTMS) , to improve the loading and control release of sulfasalazine drug bonded to APTMS. The drug release patterns from Sulfasalazine loaded HAp nanoparticles at pH value 8 For 6h, Sulfasalazine loaded functionalized HAp nanopa...
The effects of surface-functionalized Na+-montmorillonite nanoclay particles on the flexural behavior of E-glass fiber-reinforced aluminum (GLARE) laminates were investigated. The nanoclay particles were subjected to surface functionalization using 3-(trimethoxysilyl)propylamine to increase their compatibility with the epoxy matrix and improve their dispersion within the matrix. Expe...
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