Stipa capensis, the Mediterranean needle-grass, is an annual grass of the genus stipa, in the Poaceae family. It is normal found in the Persian Gulf desert ad semi-desert biome. This plant is ...indigenous to the Fars, Khuzestan, and west of Iran. In traditional medicine, stipa capensis have been used for illness related to the Nerve system problems and gastric discords. The goal of this study is to identify and characterize the phytochemical compound present in this valuable medicinal plant. This is the first report of the presence of phytochemical in stipa capensis. Stipa capensis is commonly known as Bahman in Iran. The leaves of the plant Stipa capensis was collected from Masjede-Soleiman, Khuzestan, Iran in March, 2015.Basic phytochemical screening from the aerial parts of stipa capensis revealed the presence of terpenoids and steroids. The powdered sample was extracted and was further fractionated successively with n-hexane and methanol.The nonpolar fraction was subjected to column. The separated constituents were subjected to LC-MS and GC-MS study. The spectrum of the unknown compounds was compared with the spectrum of the component stored in the NIST (National Institute Standard and Technology) library.The results pertaining to LC-MS analysis led to the identification of number of terpenes from fraction of the hexane extract of Stipa capensis.This is the first report of the screening and isolation of phytochemical in stipa capensis. This study reports the isolation and identification of terpenoid extracted from stipa capensis on fraction 1and 4 isolated that led to isolation of terpenoid compounds (carotenoids, steroids, cardiac glycosides and prenol lipids.)
A novel magnetically separable catalyst was prepared based on surface modification of Fe3O4 magnetic nanoparticle (MNPs) with polyethyleneimine (PEI) via covalent bonding. ...3-(2,3-Epoxypropoxy)propyltrimethoxysilane (EPO) was used as cross linker to bond PEI on the surface of MNPs with permanent stability in contrast to PEI coating via electrostatic interactions. The synthesized catalyst was characterized by Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). The catalyst show high efficiency for one-pot synthesis of 2-amino-3-cyano-4H-pyran derivatives via multi-component reaction (MCR). This procedure offers the advantages of green reaction media, high yield, short reaction time, easy purification of the products and simple recovery and reuse of the catalyst by simple magnetic decantation without significant loss of catalytic activity.
Covalently grafted polyethyleneimine on Fe3O4 magnetic nanoparticles as easily reusable catalyst for the synthesis of various 4H-pyrans.
Display omitted
•Polyethyleneimine modified Fe3O4 via covalent bonding as a novel water tolerance catalyst.•The catalyst showed high efficiency for one-pot synthesis of 2-amino-3-cyano-4H-pyrans in water.•Catalysts could be easily recovered and reused for several times without a significant loss in their catalytic activity.
Display omitted
•Influence of increasing N atoms on local aromaticity of azacarbazol derivatives is investigated.•The impact of changing sequence on local aromaticity of azacarbazol derivatives is ...investigated.•The insensitivity of local aromaticity to increasing N atoms and their sequence.
The influence of increasing number and changing the sequence of nitrogen atoms on the local aromaticity of azacarbazole derivatives are investigated. The local aromatic characters of the considered compounds are probed using quantitative descriptors including the geometry-based (harmonic oscillator model of aromaticity (HOMA)), magnetic index (nucleus independent chemical shift (NICSs)) and electronic based index (fluctuation delocalization index (FLU)). The aromaticity of pyrrole-like ring of the studied compounds is also analyzed through AIM theory. Furthermore, the global aromaticity of the studied azacarbazole derivatives is scrutinized using the magnetic susceptibility and HOMA together with its EN and GEO components. The obtained results indicate that the aromatic characters of these compounds are not greatly sensitive to the increasing numbers of nitrogen atoms and their sequences.
A novel nanocatalyst was developed based on covalent surface functionalization of MCM‐41 with polyethyleneimine (PEI) using 3‐(2,3‐Epoxypropoxy)propyl trimethoxysilane (EPO) as a cross‐linker. Amine ...functional groups on the surface of MCM‐41 were then conjugated with iodododecane to render an amphiphilic property to the catalyst. Palladium (II) was finally immobilized onto the MCM‐41@PEI‐dodecane and the resulted MCM‐41@aPEI‐Pd nanocatalyst was characterized by FT‐IR, TEM, ICP‐AES and XPS. Our designed nanocatalyst with a distinguished core‐shell structure and Pd2+ ions as catalytic centers was explored as an efficient and recyclable catalyst for Heck and oxidative boron Heck coupling reactions. In Heck coupling reaction, the catalytic activity of MCM‐41@aPEI‐Pd in the presence of triethylamine as base led to very high yields and selectivity. Meanwhile, the MCM‐41@aPEI‐Pd as the first semi‐heterogeneous palladium catalyst was examined in the C‐4 regioselective arylation of coumarin via the direct C‐H activation and the moderate to excellent yields were obtained toward different functional groups. Leaching test indicated the high stability of palladium on the surface of MCM‐41@aPEI‐Pd as it could be recycled for several runs without significant loss of its catalytic activity.
Functionalizing the surfaces of MCM‐41 with polyethylenimine (PEI) and 3‐(2,3‐epoxypropoxy)propyltrimethoxysilane (EPO) and its amphiphilization by Iodododecane conjugation, then the adsorption of Pd inside its shell to produce MCM‐41@aPEI‐Pd, as an efficient, selective and stable nanocatalyst for the Heck and oxidative boron Heck reactions.
A novel magnetically separable catalyst was prepared based on surface modification of Fe sub(3)O sub(4) magnetic nanoparticle (MNPs) with polyethyleneimine (PEI) via covalent bonding. ...3-(2,3-Epoxypropoxy)propyl trimethoxysilane (EPO) was used as cross linker to bond PEI on the surface of MNPs with permanent stability in contrast to PEI coating via electrostatic interactions. The synthesized catalyst was characterized by Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). The catalyst show high efficiency for one-pot synthesis of 2-amino-3-cyano-4H-pyran derivatives via multi-compo-nent reaction (MCR). This procedure offers the advantages of green reaction media, high yield, short reaction time, easy purification of the products and simple recovery and reuse of the catalyst by simple magnetic decantation without significant loss of catalytic activity.
An efficient synthesis of 6H-6-iminothiopyran-2,3-dicarboxylate and 1H-isothiochromene-3,4-dicarboxylate derivatives via one-pot reactions between acetylenic esters, aryl isothiocyanates and ...enaminones in dichloromethane at room temperature is described. The mild reaction condition, high yields and the new products are advantages of our method.
A new and highly flexible procedure is described for the synthesis of α-amino Phosphonates by
in situ generated imines or iminium salts with using dodecatungestophosphoric acid (0.5
mol%) as catalyst ...in dichloromethane at room temperature in short reaction times (<15
min).
The zwitterionic 1:1 intermediates formed from alkyl isocyanides and acetylenic esters are trapped by alkyl bromides to form 5‐alkylimino‐2,5‐dihydrofuran‐3,4‐dicarboxylate in relatively good yields ...at room temperature under solventless conditions. Hydrolysis of these compounds by HCl (5%) produced substituted furanones. J. Heterocyclic Chem., (2011).
PDF
