Nanorod Vanadatesulfuric Acid as a Novel, Recyclable and Heterogeneous Catalyst for the One-Pot Synthesis of Tetrahydrobenzopyrans
作者:Masoud Nasr-Esfahani、Tooba Abdizadeh
DOI:10.1166/jnn.2013.7592
日期:2013.7.1
Vanadatesulfuric acid (VSA), as a novel and heterogeneous nanorod catalyst, was used for an efficient synthesis of tetrahydrobenzo[b]pyrans using an aldehydes, 1,3-cyclohexanediones or β-ketoester and malononitrile in C2H5OH/H2O mixture under reflux conditions. VSA is prepared via the reaction of sodium metavanadate and chlorosulfonic acid in high purity. The catalyst was characterized by FT-IR, XRD, TEM and EDAX analysis. Compared to the conventional method, this method consistently has the advantage of high yields, simple workup, short reaction times and reusability of the catalyst.
Multi-walled carbon nanotube supported Fe3O4 nanoparticles have been prepared and characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), vibrating sample magnetometry (VSM), and transmission and scanning electron microscopy (TEM and SEM). This superparamagnetic nanocomposite, which could be conveniently separated by using an external magnet, can be used as an efficient catalyst for the promotion of the synthesis of 4H-pyran derivatives via a one-pot multicomponent reaction of an aldehyde, malononitrile and β-diketones. Some of the advantages of this work are that it is environmentally benign, has an easy work-up procedure, saves energy and uses mild reaction conditions.
Amine-functionalized hyper-crosslinked polyphenanthrene as a metal-free catalyst for the synthesis of 2-amino-tetrahydro-4 H -chromene and pyran derivatives
作者:Reddi Mohan Naidu Kalla、Anuraj Varyambath、Mi Ri Kim、Il Kim
DOI:10.1016/j.apcata.2017.03.009
日期:2017.5
the polymerization of phenanthrene using bromomethyl methyl ether as a bridging agent in the absence of any templates. The organic spheres were subjected to amine-functionalizing on the periphery of them using unreacted bromomethyl groups. The amine-functionalized microporous polyphenthrene could be employed as a highly effective and stable solid basic catalyst for the syntheses of functionalized 2-