Ni-containing l-glutamic acid cross-linked chitosan anchored on FeO/-MWCNT: a sustainable catalyst for the green reduction and one-pot two-step reductive Schotten-Baumann-type acetylation of nitroarenes.

In this research, new and eye-catching catalytic applications of the nickel (Ni) nanoparticles (NPs)-containing l-glutamic acid cross-linked chitosan anchored on magnetic carboxylic acid-functionalized multi-walled carbon nanotube (FeO/-MWCNT-CS-Glu/Ni) system, which was characterized by Fourier transform infrared (FT-IR), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), SEM-based energy-dispersive X-ray (EDX) and elemental mapping, inductively coupled plasma-optical emission spectrometry (ICP-OES), thermogravimetric analysis (TGA), differential thermal analysis (DTA), and vibrating sample magnetometry (VSM), have been introduced for the environmentally benign and efficient reduction and one-pot two-step reductive Schotten-Baumann-type acetylation of nitroarenes in water at 60 °C under an air atmosphere. It is worth noting that the Ni-containing hybrid nanocatalyst, in the mentioned organic reactions, showed short reaction times, high yields of the desired products, acceptable turnover numbers (TONs) and turnover frequencies (TOFs), and also satisfactory magnetic recycling and reusability performance even after ten times of reuse. As another significant point, all the titled organic transformations have been carried out in water as an entirely favorable and green solvent for chemical reactions.

Ni NPs entrapped within a matrix of l-glutamic acid cross-linked chitosan supported on magnetic carboxylic acid-functionalized multi-walled carbon nanotube: a new and efficient multi-task catalytic system for the green one-pot synthesis of diverse heterocyclic frameworks.

In the present study, a new l-glutamic acid cross-linked chitosan supported on magnetic carboxylic acid-functionalized multi-walled carbon nanotube (FeO/-MWCNT-CS-Glu) nanocomposite was prepared through a convenient one-pot multi-component sequential strategy. Then, nickel nanoparticles (Ni NPs) were entrapped within a matrix of the mentioned nanocomposite. Afterward, the structure of the as-prepared FeO/-MWCNT-CS-Glu/Ni nanosystem was elucidated by various techniques, including FT-IR, PXRD, SEM, TEM, SEM-based EDX and elemental mapping, ICP-OES, TGA/DTA, and VSM.

Diverse and efficient catalytic applications of new cockscomb flower-like FeO@SiO@KCC-1@MPTMS@Cu mesoporous nanocomposite in the environmentally benign reduction and reductive acetylation of nitroarenes and one-pot synthesis of some coumarin compounds.

In this research, FeO@SiO@KCC-1@MPTMS@Cu as a new cockscomb flower-like mesoporous nanocomposite was prepared and characterized by various techniques including Fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), SEM-based energy-dispersive X-ray (EDX) spectroscopy, inductively coupled plasma-optical emission spectrometry (ICP-OES), thermogravimetric analysis/differential thermal analysis (TGA/DTA), vibrating sample magnetometry (VSM), UV-Vis spectroscopy, and Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) analyses. The as-prepared FeO@SiO@KCC-1@MPTMS@Cu mesoporous nanocomposite exhibited satisfactory catalytic activity in the reduction and reductive acetylation of nitroarenes in a water medium and solvent-free one-pot synthesis of some coumarin compounds including 3,3'-(arylmethylene)bis(4-hydroxy-2-chromen-2-ones) (namely, bis-coumarins) (3a-n) and 2-amino-4-aryl-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4-chromene-3-carbonitriles (6a-n) along with acceptable turnover numbers (TONs) and turnover frequencies (TOFs). Furthermore, the mentioned Cu-containing mesoporous nanocatalyst was conveniently recovered by a magnet from reaction environments and reused for at least seven cycles without any significant loss in activity, which confirms its good stability.