Synthesis of novel pyrano[2,3-f]chromene-dione derivatives using phosphoric acid-functionalized silica-coated Fe3O4 nanoparticles as a new reusable solid acid nanocatalyst.

In this research, the synthesis of novel indeno[1,2-b]pyrano[2,3-f]chromene-2,12(13H)-dione derivatives in the presence of a newly introduced magnetically recoverable nanosolid acid catalyst is reported. At the first, phosphoric acid-functionalized silica-coated Fe3O4 nanoparticles (Fe3O4@SiO2-(CH2)3OPO3H2) were prepared and well characterized using infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), and energy-dispersive X-ray spectroscopy (EDS) techniques. Then, the catalytic activity of the prepared Fe3O4@ SiO2-(CH2)3OPO3H2 nanocatalyst was investigated for the synthesis of novel indeno[1,2-b]pyrano[2,3-f]chromene-2,12(13H)-dione derivatives via a one-pot and three-component condensation between 5,7-dihydroxy-4-methylcoumarin, indane-1, 3-dione, and various aromatic aldehydes under solvent-free condition. All the products are unknown, and their characterization was performed with the spectral data information obtained from their FT-IR, 1H and 13CNMR, elemental analysis, and their melting points. The reusability study of the introduced nanosolid acid catalyst showed that the catalytic stability is almost completely remained up to five consecutive runs.

Non-Covalent Supported of l-Proline on Graphene Oxide/Fe3O4 Nanocomposite: A Novel, Highly Efficient and Superparamagnetically Separable Catalyst for the Synthesis of Bis-Pyrazole Derivatives.

A superparamagnetic graphene oxide/Fe3O4/l-proline nano hybrid that was obtained from the non-covalent immobilization of l-proline on graphene oxide/Fe3O4 nanocomposite was used as a new magnetically separable catalyst for the efficient synthesis of 4,4'-(arylmethylene)bis(1H-pyrazol-5-ol) derivatives. The prepared heterogeneous catalyst was characterized using FTIR, TGA, DTG, XRD, TEM, SEM, and elemental analysis techniques. Short reaction times (5-15 min), excellent yields (87-98%), and simple experimental procedure with an easy work-up are some of the advantages of the introduced catalyst.

One-Pot Green Regioselesctive Synthesis of γ-Lactones from Epoxides and Ketene Silyl Acetals Using 1,3-Dimethylimidazolium Fluoride as a Recoverable Metal-Free Catalyst.

In a straightforward and fast protocol, a mixture of 1,3-dimethylimidazolium fluoride ([DMIM]F) and 1-butylimidazolium tetrafluoroborate ([Hbim]BF4) efficiently catalyzed the reaction of epoxides with ketene silyl acetals (KSA) to give various γ-lactones under metal-free conditions. Diverse kinds of the desired γ-lactones were directly prepared with high regioselectivities and yields in a simple one-pot procedure using [DMIM]F as Si-O bond activator and [Hbim]BF4 as solvent and acidic ionic liquid catalyst. The ionic liquid mixture was recovered and reused three times and no loss in its activity was observed.

Macroporous polymer supported azide and nanocopper (I): efficient and reusable reagent and catalyst for multicomponent click synthesis of 1,4-disubstituted-1H-1,2,3-triazoles from benzyl halides.

Macroporous polymer supported nanoparticles of copper(I) iodide catalyst and macroporous polymer supported azide reagent were used to simplify the synthesis of 1,4-disubstituted-1H-1,2,3-triazoles from various benzyl halides following the green chemistry principles. This new one-pot protocol facilitates the workup of the reaction and provides the products in short times and at high yields. Heterogeneous catalyst and reagent can be reloaded and reused at least for 5 runs without significant decrease in the yields.

A facile and one pot synthesis of 1,4-disubstituted-1H-1,2,3-triazoles from terminal alkynes and phenacyl azides prepared from styrenes by CAN oxidant and sodium azide.

A facile and green synthesis of 1,4-disubstituted-1H-1,2,3-triazoles is reported. The reaction of α-azido ketones and terminal alkynes in the presence of [CuSO(4) (H(2)O)(5)/sodium ascorbate] in a mixture of H(2)O/polyethylene glycol 400 as solvent afforded the corresponding 1,4-disubstituted triazoles at ambient temperature with short reaction times and at high yields. The corresponding α-azido ketones were directly prepared in situ from various substituted styrenes using the oxidant cerium ammonium nitrate and sodium azide in oxygen-saturated methanol.