Synthesis of 3,4-Dihydropyrano[c]chromenes Using Carbon Microsphere Supported Copper Nanoparticles (Cu-NP/C) Prepared from Loaded Cation Exchange Resin as a Catalyst

Abstract

Aim and Objective: The present study was performed with the aim to develop an efficient and environmentally benign protocol for the synthesis of biologically siginifcant 3, 4-dihydropyrano[c]chromenes using a new catalytic material. The protocol involves the use of a reusable, environment friendly materials and solvents with operational simplicity. Materials and Methods: Carbon microsphere supported copper nanoparticles (Cu-NP/C) prepared from loaded cation exchange resin were synthesized, characterized with well versed analytical techniques such as XRD, SEM and Raman spectroscopy and the synthesized material was used as a catalyst for the environmentally benign synthesis of 3,4-dihydropyrano[c]chromenes. Results: The formation of carbon microsphere supported copper nanoparticles (Cu-NP/C) prepared from loaded cation exchange resin was confirmed by XRD, SEM and Raman spectroscopy which was employed as a heterogeneous material for the synthesis of 3,4-dihydropyrano[c]chromenes. The products formed were characterized by the analysis of spectroscopic data - NMR, IR and mass. The safe catalytic system offers several advantages including operational simplicity, environmental friendliness, high yield, and reusability of catalyst and green chemical transformation. Conclusion: Herein we report an easy and efficient protocol for the one-pot synthesis of dihydropyrano[ c]chromenes using environmentally benign MCR approach in ethanol as the green solvent. The method developed herein constitutes a valuable addition to the existing methods for the synthesis of titled compounds.

Eco-friendly Synthesis of 1, 4-Dihydropyrano-[2,3-c] Pyrazoles Using Copper Nanoparticles Grafted on Carbon Microsphere as a Heterogeneous Catalyst

“…Mass spectrometric data were recorded by an electron spray ionization (EST) technique on a Q-tofmicro quadruple mass spectrometer (Micro mass). The catalyst synthesis and characterization have been well studied in our previous publications [35][36].…”

“…These developed catalytic metallic nanoparticles are inexpensive, non or minimally poisonous, highly active, stable, and easily separable from reaction mixture are highly useful. In our previous work, copper nanoparticles grafted on carbon microsphere (Cu-NP/C) were found to be useful for organic transformations [36][37]. In continuation of our previous work [38][39][40], herein, we report a new eco-friendly three-component protocol for the synthesis of 1,4-dihydropyrano[2,3-c] pyrazole derivatives using Cu NP/C as a heterogeneous catalyst in water and ethanol (1:1) solvent (Scheme 1).…”

A ONE POT THREE-COMPONENT SYNTHESIS OF SPIROOXOINDOLES USING Cu-NANOPARTICLES GRAFTED ON CARBON MICROSPHERES AS CATALYST

“…copper nanoparticles grafted on carbon microsphere find alternatives to these problems. 35,36 In the present work, an effective, copper nanoparticle grafted on carbon microsphere catalysed method for the one-pot synthesis of spirooxoindole derivatives in aqueous ethanol is reported herein (Scheme 1).…”