Synthesis of Nano Magnetite Fe3O4 Based Vanadic Acid: A Highly Efficient and Recyclable Novel Nano-catalyst for the Synthesis of 4,4’-(arylmethylene)-bis(3-methyl-1-phenyl-1H-pyrazol-5-ols)

Nano magnetic Fe3O4 based vanadic acid [MNPs@VO(OH)2] (average diameter 20–26 nm) has been synthesized by grafting VOCl3 on the Fe3O4 surface nanoparticles as a retrievable supporter to produce novel heterogeneous reusable solid acid with dual ability (Bronsted and Lewis acid) followed by stirring in the air. The resultant material was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) analysis and energy-dispersive X-ray spectroscopy (EDX). Significantly, the as-prepared [MNPs@VO(OH)2] exhibits a high catalytic activity in the synthesis of 4,4’-(arylmethylene)bis(3-methyl-1-phenyl-1H-pyrazol-5-ols). Additionally, the newly synthesized heterogeneous solid acid catalyst can be reused for several times without apparent loss of its catalytic activity. This work is licensed under a Creative Commons Attribution 4.0 International License

Facile preparation of a nanostructured functionalized catalytically active organosalt

We report a novel nanostructured organosalt, based on sulfonic acid functionalized pyrazinium {[H-pyrazine–SO3H]Cl2} that was synthesized and characterized by several techniques including Fourier transform infrared (FT- IR) spectroscopy, X-ray diffraction (XRD), thermal gravimetric analysis (TGA), differential thermal gravimetric (DTG) analysis, transmission electron microscopy (TEM), mass spectrometry (MS), proton NMR (1H NMR), carbon-13 NMR (13C NMR) and also electron diffraction (ED) patterns. Results proved that the unprecedented sulfonated pyrizinium organosalt is indeed nanostructured and highly crystalline as supported by TEM, ED and XRD studies, having an average nanoparticle size of 50 nm according to TEM micrographs. The novel nano- organocatalyst was proved to be an efficient catalyst in the synthesis of 1,2,4,5-tetrasubstituted imidazoles by a one-pot multi-component condensation of benzil, a broad range of aldehydes, primary amines and ammonium acetate at 90 °C under solvent-free conditions

A green non-acid-catalyzed process for direct N=N–C group formation: comprehensive study, modeling, and optimization

The aim of this work is to introduce, model, and optimize a new non-acid-catalyzed system for a direct N=N–C bond formation. By reacting naphthols or phenol with anilines in the presence of the sodium nitrite as nitrosonium (NO+) source and triethylammonium acetate (TEAA), a N=N–C group can be formed in non-acid media. Modeling and optimization of the reaction conditions were investigated by response surface method. Sodium nitrite, TEAA, and water were chosen as variables, and reaction yield was also monitored. Analysis of variance indicates that a second-order polynomial model with F value of 35.7, a P value of 0.0001, and regression coefficient of 0.93 is able to predict the response. Based on the model, the optimum process conditions were introduced as 2.2 mmol sodium nitrite, 2.2 mL of TEAA, and 0.5 mL H2O at room temperature. A quadratic (second-order) polynomial model, by analysis of variance, was able to predict the response for a direct N=N–C group formation. Predicted response values were in good agreement with the experimental values. Electrochemistry studies were done to introduce new Michael acceptor moieties. Broad scope, high yields, short reaction time, and mild conditions are some advantages of the presented method

Direct Transformation of Terminal Alkynes to Branched Allylic Sulfones

A new strategy for the transformation of terminal alkynes to branched allylic sulfones was developed. Using a Rh­(I)/DPEphos/benzoic acid catalyst system, terminal alkynes react with sulfonyl hydrazides to produce branched allylic sulfones with good to excellent yields and selectivities in general

Waste to wealth: a sustainable aquaponic system based on residual nitrogen photoconversion

A simple and innovative concept for a micro-aquaponic system (MAS) to valorize residual nitrogen via photocatalytic conversion was developed. Results proved that over 70% of ammonia could be oxidized to nitrates within 1.5 hours under UV irradiation and subsequently taken up by plants which experienced a remarkably superior plant growth (with results showing 1.8-1.6 times improved petiole growth) with respect to standard grown samples. The proposed methodology may pave the way to a new eco-farming paradigm aimed at maximizing the value of residues to valuable end-products by combining multidisciplinary efforts and low environmental impact technologies

Di-Sulfonic Acid Imidazolium Chloroaluminate, Efficiently Catalyzed the Synthesis of <i>N</i>-Sulfonyl Imines in Solventless Media with High TOF

<div><p></p><p>Di-sulfonic acid imidazolium chloroaluminate ([Dsim]AlCl₄) as a new acidic and heterogeneous catalyst was applied to the preparation of N-sulfonyl imines via the condensation of sulfonamides with aldehydes as well as isatin under solvent-free conditions. Turn-over frequency (TOF) value of the catalyst was many times better than the previous reported catalysts.</p> <p>[Supplementary materials are available for this article. Go to the publisher's online edition of <i>Phosphorus, Sulfer, and Silicon and the Related Elements</i> for the following free supplemental files: Additional text and figures.]</p> </div