In this study, the successful synthesis of periodic mesoporous organosilica containing bridged N‐sulfonic acid groups (SA‐PMO) is demonstrated. The formation and morphology of the reagent were confirmed by N2 adsorption‐desorption isotherms and pH measurement, X‐ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared (FT‐IR) analysis. After identification, the catalytic activity of this reagent was investigated in the synthesis of N,N’‐diarylformamidines, benzoxazoles, benzothiazoles and benzimidazoles. Eco‐friendly protocol, excellent yields, short reaction times, ease of preparation, reusability of the catalyst and easy isolation of the products are the main advantages of this protocol. The considerable efficiency of the catalyst can be related to its high surface area, large pore volume and high acidity.
Immobilized NaHSO4 on core/shell phenylene bridged periodic mesoporous organosilica magnetic nanoparticles (Fe3O4@Ph-PMO-NaHSO4) as a new acidic magnetically separable nanocatalyst was successfully prepared in three steps: (i) preparation
of Fe3O4 nanoparticles by a precipitation method, (ii) synthesis of an organic–inorganic periodic mesoporous organosilica structure with phenyl groups on the surface of Fe3O4 magnetic nanoparticles (MNPs) and (iii) finally adsorption of NaHSO4
on periodic mesoporous organosilica (PMO) network. The prepared organic–inorganic magnetic reagent was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption–desorption and
energy-dispersive X-ray (EDX) techniques. Finally, it was used as a reusable and new catalyst to promote the synthesis of tetrahydrobenzo[b]pyran and pyrano[2,3-d]pyrimidinone derivatives as important biologically active compounds. Eco-friendly protocol, high yields, short reaction
times and easy and quick isolation of the products are the main advantages of this procedure.
We clicked a salen ligand onto a thiol‐ethane bridged periodic mesoporous organosilica (Salen‐PMO) using a photo‐initiated thiol‐ene click reaction. This process resulted in a covalently bonded salen ligand on the PMO material. The final BET surface area amounts 511 m2/g and the pore size diameter is approximately 7 nm. The functionalized PMO material showed an excellent carbon dioxide uptake capacity of 1.29 mmol/g at 273 K and 1 bar. More importantly, by coordinating a MoO22+ complex onto the Salen‐PMO material, we obtained a heterogeneous catalyst with a good catalytic performance for the epoxidation of cyclohexene. The catalyst was highly reusable, as no decrease in its activity was observed for at least four runs (99% conversion). Finally, the metal‐free Salen‐PMO showed an exceptional catalytic performance in the cycloaddition of CO2 to epoxides. The obtained results clearly demonstrate the versatility of the Salen‐PMO material not only as metal‐free catalyst but also as a support material to anchor metal complexes for specific catalytic applications. With the same catalytic platform, we were able to firstly create epoxides out of alkenes, and subsequently turn these epoxides into cyclic carbonates, consuming CO2.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.