Gold nanoparticle functionalized mesoporous silica-chitosan (Au NPs/silica-chitosan) as an
environmentally benign and heterogeneous nanocatalyst was prepared and its properties were characterized
using field emission scanning electron microscopy (FE-SEM) and fourier transform infrared
(FT-IR). The catalytic activity of Au NPs/silica-chitosan was studied in the synthesis of biologically
important 4H-pyran derivatives. In these reactions, efficient and green syntheses of 4H-pyrans were
carried out using isatins or aldehydes, active methylene compounds, and 1,3-dicarbonyl compounds in
the presence of a catalytic amount of Au NPs/silica-chitosan in water in excellent yields. Au
NPs/silica-chitosan can be recovered easily and reused without any significant loss of the catalytic activity.
4H-pyran derivatives were synthesized using Au NPs/silica-chitosan as catalyst in three component
reaction of isatins/aldehydes, active methylene, and 1,3-dicarbonyl compounds in water. Au
NPs/Silica-Chitosan was prepared by reaction of aqueous solution of HAuCl4 (1 wt.%) and solution
chitosan in deionized water and acetic acid with tetraethyl ortho silicate (TEOS) at 100ºC for 24 h.
Gold nanoparticle functionalized mesoporous silica-chitosan was prepared and its catalytic activity was
investigated for forming 4H-pyran derivatives. In this study, active methylene and 1,3-dicarbonyl compounds
reacted with various isatins and aldehydes which afforded the corresponding spirooxindoles
with 88-98% yields. This method includes the environmentally friendly reaction conditions, short reaction
time, simple work-up, excellent yield, broad scope of usable substrates, recovery and reusability of
heterogeneous catalyst.
In situ synthesis of CuO nanoparticles over functionalized mesoporous silica and their application in catalytic syntheses of symmetrical diselenides