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A new approach has been developed for environmentally friendly C-C cross-coupling reactions using bi-functional Pd(ii)-salen complex-embedded cellulose filter paper (FP@Si-Pd II -Salen-[IM]OH). A Pd(ii)-salen complex bearing imidazolium [OH] - moieties was covalently embedded into a plain filter paper, then used as an efficient portable catalyst for the Heck, Suzuki, and Sonogashira cross-coupling reactions under environmentally friendly conditions via the filtration method. The catalytic filter paper properties were studied by EDX, XPS, TGA, ATR, XRD, and FESEM analyses. The reactions were catalyzed during reactants' filtration over the catalytic filter paper. The modified filter paper was set up over a funnel and the reactants were passed through the catalytic filter paper several times. The effect of reaction parameters including loading of Pd(ii)-salen complex, temperature, solvent, and contact time were carefully studied and also the optimal model of conditions was presented by the design expert software. High to excellent yields were obtained for all C-C coupling types with 5 to 8 filtration times. Under optimal conditions, all coupling reactions showed high selectivity and efficiency. Another advantage of the modified filter paper was its stability and reusability for several times with preservation of catalytic activity and swellability., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Saponin, as a green and available phytochemical, was immobilized on the surface of magnetite nanoparticles then doped with Cu ions (Fe 3 O 4 @Sap/Cu(ii)) and used as an efficient nanocatalyst for the synthesis of quinazoline and acridine derivatives, due to their high application and importance in various fields of science. Different spectroscopic and microscopic techniques were used for the catalyst characterization such as FT-IR, XRD, FE-SEM, EDX, TEM, TGA, VSM, BET, DLS, CV, and XPS analyses. All characterization data were correlated with each other so that the structure of the catalyst was accurately characterized. The reactions were performed in the presence of a low amount of Fe 3 O 4 @Sap/Cu(ii) (0.42 mol%) as a green catalyst in water over a short period of time. The results show well the effective role of saponin in solving the problem of mass transfer in aqueous medium, which is the challenge of many organic reactions in aqueous medium and in the presence of heterogeneous medium. High catalytic activity was found for the catalyst and high to excellent efficiency was obtained for all quinazoline (68-94% yield) and acridine (66-97% yield) derivatives in short reaction times (less than 1 hour) under mild reaction conditions in the absence of any hazardous or expensive materials. There is not any noticeable by-product found whether for acridine or quinazoline derivatives, which reflects the high selectivity. Two reasonable mechanisms were proposed for the reactions based on observations from control experiments as well as literature reports. The catalyst could be easily recovered magnetically for at least six consecutive runs with insignificant reactivity loss., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

A new, versatile, and green methodology has been developed for the efficient NaBH 4 -reduction of nitroarenes as well as the domino/reduction MCR preparation of 1-substituted-1 H -1,2,3,4-tetrazoles using Pd(ii)-polysalophen coated magnetite NPs as an efficient heterogeneous magnetically recyclable nanocatalyst. Polysalophen was firstly prepared based on a triazine framework with a high degree of polymerization, then coordinated to Pd ions and, finally, the resulting hybrid was immobilized on magnetite NPs. The catalyst was characterized by various instrumental and analytical methods, including GPC, DLS, N 2 adsorption-desorption, TGA, VSM, TEM, HRTEM, EDX, XPS, XRD, and ICP analyses. The catalyst possesses dual-functionality including the reduction of nitroarenes and the construction of tetrazole rings all in one step via a domino protocol. High to excellent yields were obtained for both nitro reduction and the direct preparation of 1-substituted-1 H -1,2,3,4-tetrazoles from nitro compounds. Insight into the mechanism was conducted by XPS in situ as well as DLS in situ along with several control experiments. Recyclability of the catalyst was studied for 6 consecutive runs along with metal leaching measurements in each cycle., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Herein, the synthesis and application of copper-incorporated sulfated zirconium oxide supported on CuFe 2 O 4 NPs (CuFe 2 O 4 @SiO 2 @ZrO 2 /SO 4 2- /Cu NPs) as a novel Lewis/Brønsted acid nanocatalyst were studied for the Sonogashira C-C cross-coupling reaction. The fabricated CuFe 2 O 4 @SiO 2 @ZrO 2 /SO 4 2- /Cu catalyst exhibited efficient activity for a large variety of aryl iodides/bromides and, most importantly, aryl chlorides in water and in the presence of NaOH as a base in short reaction times. The catalyst was fully characterized by FTIR, TG-DTG, VSM, XRD, EDX, FE-SEM and TEM analyses. A synergetic effect could be considered to have arisen from the various Lewis acid and Brønsted acid sites present in the catalyst. The efficient incorporation of copper into zirconia provided a robust highly stable hybrid, which prevented any metal leaching, whether from the magnetite moiety and/or Cu sites in the reaction mixture. Moreover, the catalyst was successfully recovered from the mixture by a simple external magnet and reused for at least 9 consecutive runs. Zero metal leaching, stability, consistency with a variety of substrates, fast performance, cost-effectiveness, environmental friendliness, and preparation with accessible and cheap materials are some of the advantages and highlights of the current protocol., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)