Photocatalytic synthesis of 2-methylquinolines with TiO2 Wackherr and Home Prepared TiO2 – A comparative study

A comparative study was carried out on the efficiency of titanium dioxide specimens Wackherr TiO2, prepared TiO2 and Aeroxide P25 toward the photocatalytic synthesis of pharmaceutically important 2-methylquinolines. TiO2 Wackherr induced significantly faster conversion of nitrobenzene to 2-methylquinoline than Aeroxide P25 when high photocatalyst loadings and high substrate concentrations were used. Photocatalytic synthesis of 2-methylquinolines from substituted nitrobenzenes and anilines show that the product yield is not significantly influenced by the substituents. Low cost TiO2 Wackherr is more useful when high photocatalyst loading is required at high substrate concentration

Citrate Functionalized Zirconium-Based Metal Organic Framework for the Fluorescent Detection of Ciprofloxacin in Aqueous Media

Ciprofloxacin (CIP) is a commonly used antibiotic for the treatment of infectious diseases in humans and as a prophylactic agent in the livestock industry, leading to the environmental discharge of significant amounts of CIP. CIP is stable in aquatic systems leading to its pseudo-persistence. Constant exposure to these antibiotics results in the generation of antibiotic-resistant pathogens and potential toxicity/hypersensitivity in humans. Therefore, it is necessary to develop a convenient, rapid, and cost-effective method for the monitoring of ciprofloxacin in environmental samples. Rhodamine-based fluorescent receptors have the limitation of aqueous solubility. Therefore, in order to overcome this drawback, we designed a novel fluorescent receptor based on a zirconium-based metal organic framework (MOF-808). The precursor, MOF-808, was synthesized and functionalized by using sodium citrate to obtain a receptor called C-MOF-808. The C-MOF-808 was structurally characterized by XRD and spectroscopic analyses. Thus, this synthesized receptor can be used for the fluorescent detection of CIP in aqueous media with a detection limit of 9.4 µM. The detection phenomena of the receptor were studied by absorption as well as fluorescent spectra. The binding behavior of CIP with the receptor was studied by FT-IR and 1H-NMR analyses, and a binding mechanism is proposed

Spatiotemporal Control of Amide Radicals During Photocatalysis

Despite the continuing popularity of radical reactions in organic synthesis, much remains to be explored in this area. Herein, we describe how spatiotemporal control can be exerted over the formation and reactivity of divergent exchangeable formamide radicals using nickel complexes with a semiconductor material (TiO2) under irradiation from near-UV–Vis light. Depending on the bipyridine ligand used and the quantity of the nickel complex that is hybridized on or nonhydridized over the TiO2 surface, these radicals selectively undergo substitution reactions at the carbon center of carbon–bromine bonds that proceed via three different pathways. As the scalable production of formamides from CO2 does not produce salt waste, these methods could add a new dimension to the search for carbon neutrality through the indirect incorporation of CO2 into organic frameworks

Diboron-Catalyzed Dehydrative Amidation of Aromatic Carboxylic Acids with Amines

Tetrakis­(dimethylamido)­diboron and tetrahydroxydiboron are herein reported as new catalysts for the synthesis of aryl amides by catalytic condensation of aromatic carboxylic acids with amines. The developed protocol is both simple and highly efficient over a broad range of substrates. This method thus represents an attractive approach for the use of diboron catalysts in the synthesis of amides without having to resort to stoichiometric or additional dehydrating agents

Ru Nanoparticles Supported on Mesoporous Al-SBA-15 Catalysts for Highly Selective Hydrogenation of Furfural to Furfuryl Alcohol

This is an open access article under the terms of the Creative Commons Attribution Non-Commercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.Furfuryl alcohol, which is the hydrogenated product of furfural, has been identified as a very promising platform chemical with high potential for applications in the manufacture of key chemicals, lubricants, fragrances, and pharmaceuticals. In this work, bare SB, and x % Ru/Al-SB (x=1.5, 2.5, 3.5, and 4.5 wt. %) samples were fabricated by a hydrothermal method. Bare and most active catalysts were characterized by different techniques, such as BET, FE-SEM, TEM, FT-IR, and XRD, to understand their physical and chemical properties. An evaluation of the effects of various reaction parameters, such as catalyst loading, reaction temperature, and reaction time, on the catalytic performance, showed higher catalytic conversion of furfural and selectivity for the desired products. The most active RuS3 catalyst showed 100 % conversion of furfural and 99 % selectivity for furfuryl alcohol. It could be reused for five consecutive reaction cycles without significant loss of performance. In addition, Ru leaching and loss of conversion or selectivity were not noticed during the five-run recycling test. The EDS elemental mapping analysis of the used catalyst established the preservation of the mesoporous structure, suggesting a strong interaction between the hexagonal porous silicate and the Ru nanoparticles

Synthesis of Dicarboxylic Acids Comprising an Ether Linkage and Cyclic Skeleton and Its Further Application for High-Performance Aluminum Electrolyte Capacitors

Aluminum electrolytic capacitors are essential components in all electronic devices, and it is known that their longevity depends on the performance of their electrolytes. We synthesized dicarboxylic acids having ether bonds showing the good solubility in ethylene glycol as a solvent and simultaneously developed a complete halogen removal method, which is strictly prohibited in capacitors. Moreover, the incorporation of bulky α-substituents and cyclic structures dramatically improved their heat resistance and can withstand high voltage, i.e., 764 V