Silver nanoparticles-decorated Preyssler functionalized cellulose biocomposite as a novel and efficient catalyst for the synthesis of 2-amino-4H-pyrans and spirochromenes

Sara Saneinezhad,Vahideh Zadsirjan,Leila Mohammadi,Majid M Heravi,Fatemeh F Bamoharram

doi:10.1038/s41598-020-70738-z

Sara Saneinezhad, Vahideh Zadsirjan + Show 3 more

Open Access

https://doi.org/10.1038/s41598-020-70738-z

Copy DOI

Abstract

Silver nanoparticles-decorated Preyssler functionalized cellulose biocomposite (PC/AgNPs) was prepared and fully characterized by FTIR, UV–vis, SEM, and TEM techniques. The preparation of PC/AgNPs was studied systematically to optimize the processing parameters by Taguchi method using the amount of PC, reaction temperature, concentration of silver nitrate and pH of medium. Taguchi’s L9 orthogonal (4 parameters, 4 level) was used for the experimental design. The SEM analysis confirmed the presence of the Preyssler as a white cloud as well as spherical AgNPs on the surface of cellulose. The formation of AgNPs on the surface was observed by changing of the color from yellow to deep brown and confirmed by UV–vis spectroscopy. The best yield of AgNPs forming was obtained in pH 12.5 at 80 ºC in 20 min. TEM analysis confirmed the formation of spherical AgNPs with a size of 50 nm, at the 1% wt. loading of Preyssler. This easily prepared PC/AgNPs was successfully employed as an efficient, green, and reusable catalyst in the synthesis of a wide range of 2-amino-4H-pyran and functionalized spirochromene derivatives via a one-pot, multicomponent reaction. The chief merits realized for this protocol were the utilization of commercially available or easily accessible starting materials, operational simplicity, facile work-up procedure, obtaining of high to excellent yields of the products and being done under green conditions. The catalyst could be easily separated from the reaction mixture and reused several times without observing any appreciable loss in its efficiency.

Highlights

With increasing concern about environmental pollution, the development of new heterogeneous catalytic systems based on green and biodegradable solid supports have attracted much attention of chemical community
Literature survey shows among different heterogeneous catalytic reactions, many investigations have been devoted to develop methodologies based on the use of metal nanoparticles supported onto cellulose due to its
We achieved an effective strategy for the designing and in situ synthesis of an organic–inorganic polymeric bio-composite involving functionalized microcrystalline cellulose and Preyssler HPA for immobilization of Pd nanoparticles on the surface to the formation of nanobiocomposite as surface heterogeneous composite and used it in successful degradation of azo dyes[45]

Summary

Results and discussion

The interrelationship between the existed parameters for synthesis of nanoparticles to optimize the factors is a time and labor consuming work. The effects of silver nitrate concentration, temperature, pH and different loadings PC on the UV–Vis analysis of silver nanoparticles at four different levels (1, 2, 3 and 4) were investigated in Fig. 2 and “plot” is a verb in this context Control factors are those design and process parameters that can be controlled in Taguchi method. With Taguchi experimental conditions (Table 2), including in situ one-pot synthesis of AgNPs without additional reducing agents was checked, showing a promising green catalyst with different loading of preyssler to prepare a new nanobiocomposite to catalyze the synthesis of 4H-pyrans. Three-component reaction of substituted aromatic aldehydes, malononitrile or ethylcyanoacetate and dimedone mediated by PC/AgNPs refluxing EtOH/H2O was successfully giving the expected corresponding products in satisfactory yields. We examined the three-component reaction of different aromatic aldehydes, malononitrile or ethylcyanoacetate and 4-hydroxycoumarin in the presence of PC/AgNPs as an effective catalyst in EtOH/H2O under reflux condition.

CN CN CN CN CN CN CN CN CO2Et CO2Et CO2Et CO2Et CO2Et CO2Et

CN CN CN CN CN CN CO2Et CO2Et CO2Et CO2Et CO2Et

CN CN CN CN CN CN CN CN CN CO2Et CO2Et CO2Et

Conclusions