Palladium (0) Nanoparticles: A Novel and Reusable Catalyst for the Synthesis of Various Pyran Derivatives

Mithu Saha,Amarta Kumar Pal

doi:10.4236/anp.2012.13009

Abstract

A ligand free, Palladium nanoparticles catalyzed synthesis of pyran derivatives using C-H activated compound, malononitrile and aryl aldehyde via Knoevenagel condensation followed by Michael addition reaction using Palladium nanoparticles as catalyst in one-pot is described herein. The advantages of this method lie in its simplicity, low catalyst loading, cost effectiveness and easy to handle. The Palladium Nanoparticles can be reused without loss of activity even after recycling four times. The palladium nanoparticles were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM). The present method also allows us to synthesize highly functionalized title compounds from simple and readily available inputs.

Highlights

Pyran derivatives are of considerable interest in industry as well as in academia owing to their promising biological activity such as anticoagulant, anticancer, diuretic, spasmolytic and anti-anaphylactin agents. [1] recent studies have revealed several medicinal applications such as, for the treatment of alzheimer’s disease, Huntington’s disease, amyoprophic lateral sclerosis, Parkinson’s diseases, AIDS associated dementia and Down’s syndrome as well as for the treatment of schizophrenia and myoclonus. [2,3] These heterocycles are used as cosmetics, pigments and biodegradable agrochemicals and photoactive materials. [4,5] A considerable effort has been made for the synthesis of pyran annulated heterocyclic derivatives due to their wide applications
A ligand free, Palladium nanoparticles catalyzed synthesis of pyran derivatives using C-H activated compound, malononitrile and aryl aldehyde via Knoevenagel condensation followed by Michael addition reaction using Palladium nanoparticles as catalyst in one-pot is described
The palladium nanoparticles were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM)

Summary

Introduction

Pyran derivatives are of considerable interest in industry as well as in academia owing to their promising biological activity such as anticoagulant, anticancer, diuretic, spasmolytic and anti-anaphylactin agents. [1] recent studies have revealed several medicinal applications such as, for the treatment of alzheimer’s disease, Huntington’s disease, amyoprophic lateral sclerosis, Parkinson’s diseases, AIDS associated dementia and Down’s syndrome as well as for the treatment of schizophrenia and myoclonus. [2,3] These heterocycles are used as cosmetics, pigments and biodegradable agrochemicals and photoactive materials. [4,5] A considerable effort has been made for the synthesis of pyran annulated heterocyclic derivatives due to their wide applications. Pyran derivatives are of considerable interest in industry as well as in academia owing to their promising biological activity such as anticoagulant, anticancer, diuretic, spasmolytic and anti-anaphylactin agents. [4,5] A considerable effort has been made for the synthesis of pyran annulated heterocyclic derivatives due to their wide applications. The use of palladium nanoparticles has recently received considerable attention in the synthesis of various important heterocycles. The ability of nanotechnology to enhance catalytic activity opens the potential to replace expensive catalysts with lower amounts of inexpensive nanocatalysts. Our literature survey at this stage revealed that, there are no reports yet available on the synthesis of pyrans derivatives in one-pot catalyzed by Pd nanoparticles. We report here a novel, ligand-free protocol for synthesis of pyran derivatives catalyzed by palladium(0) nanoparticles

Apparatus

Result and Discussion

Findings

Conclusion