Ferrite-supported glutathione: an efficient, green nano-organocatalyst for the synthesis of pyran derivatives

Abstract

An efficient magnetically retrievable ferrite-supported glutathione nano-organocatalyst has been employed for the synthesis of a library of 2-amino-4H-pyran derivatives in aqueous medium via one-pot, multicomponent reaction. The highlight of this protocol lies in its operational simplicity, use of greener solvent, high yield within very short period of time and reusability of the catalyst. This method provides an alternative greener approach for the synthesis of 2-amino-4H-pyran derivatives.

Magnetic Nanoparticles Functionalized with Copper Hydroxyproline Complexes as an Efficient, Recoverable, and Recyclable Nanocatalyst: Synthesis and Its Catalytic Application in a Tandem Knoevenagel–Michael Cyclocondensation Reaction

“…Although MNPs are nontoxic and could be easily prepared, − low thermal and chemical stability in environmental conditions limits their applications. However, immobilization of these MNPs with a nitrogen-impermeable scabbard is a necessary prerequisite for their potential use in catalyst support and biomedical applications. − Because of their low toxicity, superparamagnetic behavior, and large surface-area-to-volume ratio, MNPs have attracted significant attention in various technological fields. − In recent years, multicomponent reaction (MCR) has emerged in organic synthesis because of the ability to combine three or more starting materials in a flask for the synthesis of a new product. − In fact, one of the most effective procedures for the synthesis of complex structures from simple and available starting materials is MCR, , which has been extensively used in the synthesis of natural product, organic material, and biologically active molecules thanks to some prominent features such as low waste production, high convergence, and high atomic economy. − The main part of a large number of natural products and chemical molecules is 4 H -pyran and its derivatives. In fact, pyrans and fused pyrans are biologically attractive compounds (Scheme ) because of their antibacterial, − antifungal, antimicrobial, spasmolytic, anticoagulant, antianaphylactic diuretic, − and antitumor activities.…”

Recent advances in organo-nanocatalysis in the field of green organic synthesis

“…In monolayer organo-nanocatalysts, the organic moiety has a strong bonding affinity with the metal nanosurface, and hence there is no requirement for an intermediate coating. 67,68,69 In multilayer organonanocatalysts, the need for an intermediate coating arises due to weak bonding interaction between the organic moiety and the metal nanoparticles. 70,47,8 In order to ensure that the organic moiety is firmly attached to the surface of the nanoparticle, it is recommended to coat the nano-magnetic particles with an intermediate moiety which has strong bonding affinity with both the nano core and the organic moiety.…”

“…Fe 3 O 4 @glutathione NPs were synthesized by many research groups as follows. 11,67,86,87,88 A portion of 0.5 g of Fe 3 O 4 nanoparticles, prepared in the usual way, was dispersed in 20 mL of water-ethanol mixture (3:1) using ultrasonication. Glutathione (0.5 g in 5 mL water) was added, and the reaction mixture was ultrasonicated at room temperature for 2 hours.…”

“…86 Luque et al developed a synthetic method of aqueous homocoupling of arylboronic acids under microwave irradiation using magnetically separable ferrite-anchored glutathione nanoparticles (Scheme 21). 67 Dam et al synthesized fused phthalazinetriones (57) and phthalazinediones (58) derivatives from phthaIic anhydride (54), hydrazine hydrate (55), aIdehydes (15) and active methyIene compounds After the complete addition of the organosilane precursor the reaction mixture was kept under refluxing conditions for about 12 hours under a nitrogen atmosphere. After the completion of the reaction, the reaction mixture was allowed to cool at room temperature.…”

A new direction in the alkylation of 5‐acetyl‐2‐amino‐6‐methyl‐4‐phenyl‐4H‐pyran‐3‐carbonitrile with active methylene reagents

“…It is known from the literature that substituted pyrans show antitumor, antibacterial, antiviral, antispasmodic, antifungal, and anti‐inflammatory properties . According to numerous published works, a convenient synthesis route to 4 H ‐pyrans is based on the Michael reaction of benzylidenemalononitriles with active methylene compounds under various conditions (Scheme ) …”