Sulfonated carbons from agro-industrial residues: simple and efficient catalysts for the Biginelli reaction

Abstract

The Biginelli reaction is a one-pot acid-catalyzed cyclocondensation of an aromatic aldehyde, urea, and ethyl acetoacetate to synthesize dihydropyrimidinones (DHPMs). DHPMs are extremely important due to their wide-ranging pharmacological activities,...

Ionic Liquid Supported on Magnetic Graphene Oxide as a Highly Efficient and Stable Catalyst for the Synthesis of Triazolopyrimidines

“…46,47 Several synthetic strategies have been described for the preparation of triazolopyrimidine derivatives, most of which are based on a modification of the classical Biginelli reaction. 48,49 Although some of these procedures are efficient, some of them have limiting factors, including long reaction times, side reactions, rigid workup, high-temperature conditions, and nonrecyclable reagents.…”

Sorption and Desorption Performance of La3+/Bi3+ by Surface-Modified Activated Carbon for Potential Application in Medical 225ac/213bi Generators

“…The carbon 1s spectra (Fig. 3a) of the samples exhibited a similar profile at low binding energy, while the peak in the range of 288-290 eV became more visible with the increase in sulfonation temperature [51]. This implies that high-density carboxylic acid groups were introduced into SNCAs at high sulfonation temperatures.…”

l-Asparagine–EDTA–amide silica-coated MNPs: a highly efficient and nano-ordered multifunctional core–shell organocatalyst for green synthesis of 3,4-dihydropyrimidin-2(1H)-one compounds

“…Among the various types of nitrogen-containing heterocycles, derivatives of 3,4-dihydropyrimidin-2(1 H )-one, as biologically-active compounds, have found versatile applications such as anti-bacterial, anti-inflammatory, antihypertensive agents, calcium channel blockers and antitumor compounds. 52–60 A simple and general protocol for access to 3,4-dihydropyrimidin-2(1 H )-ones involves the three-component and one-pot Biginelli cyclocondensation of ethyl acetoacetate, urea and various aldehydes accelerated by different types of acidic catalytic systems such as copper( ii ) trifluoromethanesulfonate under microwave irradiation, 61 gallium( iii ) triflate, 62 bismuth pyromanganate nanoparticles, 63 l -proline methyl ester hydrochloride, 64 nanometasilica disulfuric acid, 65 p -toluenesulfonic acid, 66,67 sulfonic acid-supported polymeric catalysts, 68 sulfonated carbons from agro-industrial wastes, 69 phenylboronic acid, 70 1,3-bis(carboxymethyl)imidazolium chloride, 71 sulfonic acid and ionic liquid functionalized covalent organic frameworks, 72 ionic liquid combined with acidic zeolite-supported heteropolyacids, 73 ionic liquid/silica sulfuric acid, 74 bentonite/PS-SO 3 H nanocomposite, 75 dendrimer-attached phosphotungstic acid immobilized on nanosilica under ultrasonication, 76 tungsten-substituted molybdophosphoric acid impregnated with kaolin, 53 zinc- and cadmium-based coordination polymers, 77 metal–organic frameworks (MOFs), 78,79 montmorillonite clay, 80 magnetic nanoparticles, 81 Lewis acidic zirconium( iv )–salophen perfluorooctanesulfonate or sulfated polyborate, 82,83 nanocrystalline CdS thin film, 59 graphene oxide, 84,85 and mesoporous materials. 86,87 Most of the reported methods in this regard demonstrate valuable role of heterogeneous catalysts.…”