An efficient ‘on-water’ synthesis of 1,4-dihydropyridines using Fe3O4@SiO2 nanoparticles as a reusable catalyst

Synthesis of heterocycles and fused heterocycles catalyzed by nanomaterials

“…116 The same authors have developed this synthetic method for the preparation of bis-2H-indazolo[2,1b]phthalazine-trione 146 derivative in a 2:1.1:2 molar ratio of phthalhydrazide to isophthaladehyde and dimedone ( 146a 146b 146c 146d 146e 146f 146g 146h 146i 146j 146k 146a 146l 146i 146h 146j 146m 146n 146o 146b 146p 146q 146k 146r 146c 146s 146t 146u 146v 146w 146x 146y 146a 146b 146j 146c 146i 146e 146z 146c 146b 146r 146aa 146ab Yield (%) Table 69). 110 The nature and position of substitution in the aromatic ring did not affect the reactions much. …”

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

“…Large surface area, strong metal‐support interactions and the presence of active sites that can participate in the consecutive reaction steps are the essential requirements for an appropriate support . Inorganic metal oxides, especially SiO 2 , as well as organic polymers or active carbons that display large surface areas are typically used insoluble solid supports for the magnetic heterogeneous catalysts . Among others, the unique features of suspensions of graphene oxide (GO) have provided a new horizon for the expansion of supported MNPs as heterogeneous catalysts.…”

“…[36,37] Inorganic metal oxides, especially SiO 2 , as well as organic polymers or active carbons that display large surface areas are typically used insoluble solid supports for the magnetic heterogeneous catalysts. [31,38,39] Among others, the unique features of suspensions of graphene oxide (GO) have provided a new horizon for the expansion of supported MNPs as heterogeneous catalysts.…”

Green synthesis of polyhydroquinolines catalyzed by silica‐supported ionic liquid Si–[SbSipim][PF6]

“…The Hantzsch reaction for the synthesis of polyhydroquinolines involves one‐pot condensation of an aldehyde with β‐ketoester and NH 3 in AcOH or in alcohol under reflux for several hours . This reaction has subsequently been promoted by employing different catalysts, such as nano‐CuO, ZnO, nano‐Fe 3 O 4 @SiO 2 , Ni nanoparticles, lewis acid, Mg(ClO 4 ) 2 or Yb(OTf) 3 , and ionic liquid . In recent years, supported ionic liquid catalysts (SILCs) have been an attractive research area .…”