A practical and highly efficient synthesis of densely functionalized nicotinonitrile derivatives catalyzed by zinc oxide‐decorated superparamagnetic silica attached to graphene oxide nanocomposite

Abstract

Zinc oxide‐decorated superparamagnetic silica attached to graphene oxide (Fe3O4/SiO2/PTS‐GO‐ZnO), as a novel nanocomposite, was designed, and its core‐shell structure was appropriately characterized by different spectroscopy or microscopy methods and thermal techniques as well as measuring of its porosity and magnetic properties. The catalytic activity of Fe3O4/SiO2/PTS‐GO‐ZnO, as a reusable heterogeneous catalyst, was investigated for efficient one‐pot multi‐component synthesis of medicinally important functionalized 2‐amino‐6‐(2‐oxo‐2H‐chromen‐3‐yl)‐4‐arylnicotinonitrile derivatives. The significant features of the present procedure are mild reaction conditions, low loading of the catalyst, high to quantitative yields of the desired products, avoiding the use of toxic heavy metals or solvents, simple isolation and purification of the products, and stability as well as reusability of the catalyst after at least six consecutive runs.

Dendrons containing boric acid and 1,3,5-tris(2-hydroxyethyl)isocyanurate covalently attached to silica-coated magnetite for the expeditious synthesis of Hantzsch esters

“…On the other hand, absorption band of Si–O–Si asymmetric stretching vibrations are apparent at around 1076 cm −1 . Furthermore, the observed signals at 954, 802 and 459 cm –1 are assigned to the symmetric stretching and bending vibrations of Si–O–Si bond 43 , 57 , 124 . Also, the absorption band of C=O bond vibrations of the isocyanurate moiety appeared at around 1637 cm −1 77 , 120 , 125 .…”

Recent advancements in organic synthesis catalyzed by graphene oxide metal composites as heterogeneous nanocatalysts

“…A novel, green, and highly effective recyclable catalyst (Fe 3 O 4 /SiO 2 /PTS‐GO‐ZnO) (50 mg) for the synthesis of nicotinonitrile derivatives was performed using one‐pot multicomponent condensation reaction of 3‐acetylcoumarin, various aldehydes, NH 4 OAc, and malononitrile at 100°C under solvent‐free conditions by Davoodi et al [ 197 ] (Scheme 32). Different catalysts were compared with Fe 3 O 4 /SiO 2 /PTS‐GO‐ZnO for the synthesis of nicotinonitrile derivatives such as GO, magnetic cellulose/Ag, iron(III) phosphate, trifluoroethanol, and acetic acid and the synthesized catalyst produced excellent yields (97%) in a very short reaction time.…”

Greener design and characterization of biochar/Fe3O4@SiO2–Ag magnetic nanocomposite as efficient catalyst for synthesis of bioactive benzylpyrazolyl coumarin derivatives

“…Functionalization and surface modification with organic or inorganic supports are required to address these issues and boost their effectiveness for the specific application. 17–22…”