A novel and reusable magnetic nanocatalyst developed based on graphene oxide incorporated strontium nanoparticles for the facial synthesis of β‐enamino ketones under solvent‐free conditions

Abstract

A novel magnetic SrFeGO nanocatalyst (NC) was synthesized through a simple sol-gel technique by introducing strontium and iron oxide nanoparticles onto graphene. The synthesized NC was characterized using FT-IR and FE-SEM. Subsequently, the catalytic activity of SrFeGO was tested in a reaction between β-dicarbonyl compounds and aniline derivatives to gain β-enamino ketone derivatives under solvent-free conditions. It was found that SrFeGO NC is a potential catalyst for the synthesis of β-enamino ketones. The β-enamino ketone produced by such reactions could be isolated in high purity without the need for chromatographic purifications. The newly prepared magnetic graphene oxide nanocomposite could be recovered and reused for numerous times with no significant decrease in efficiency. Moreover, the protocol has the advantages of excellent yielding (up to 98%) in short a reaction time, benefitting an easy workup procedure and being environmentally friendly.

Zirconium@guanine@MCM‐41 nanoparticles: An efficient heterogeneous mesoporous nanocatalyst for one‐pot, multi‐component tandem Knoevenagel condensation–Michael addition–cyclization Reactions

“…The present study investigates an efficient, facile, and environmentally friendly procedure for one-pot tandem Knoevenagel condensation-Michael addition-cyclization reactions in order to synthesize benzo[a]benzo [6,7] In order to establish the feasibility of this protocol and find the optimal conditions for the synthesis of benzo[a]benzo [6,7] [6,7]chromeno [2,3-c] phenazine] derivatives, we explored the reaction of 2-hydroxy-1,-4-naphthoquinone, benzene-1,2-diamines, and 4-chlorobenzaldehyde as the model reaction. We also aimed at investigating the effect of different reaction parameters such as the amount of the catalyst, nature of solvents and reaction temperature on the rate of the chemical reaction and the yield of products (Scheme 2).…”

“…Therefore, in order to find the best temperature, we investigated the reaction efficiency in various temperatures. Besides, it was noted that the temperature played an important role on the outcome of the reaction in the synthesis of 17-(4-chlorophenyl)-11H-benzo[a]benzo [6,7] chromeno[2,3-c]phenazine-11,16(17H)-dione. As a result, 100 C was selected as the best temperature for this reaction (Table 2, entry 5).…”

“…[4,5] Multicomponent reactions (MCRs) have come out as a powerful tool in modern synthetic organic chemistry and provide a solution to overcome the mentioned disadvantages. [4,[6][7][8][9] In this respect, it is significant to note that the benefits of multi-component reactions (MCRs) in combinatorial chemistry are highly regarded in nature; as they are essential to life and minimize the waste production, time, cost and labor. [10,11] These reactions have become a strong synthetic methodology for the rapid preparation of small-molecule libraries that reduce the number of synthetic steps and can be obtained in one pot with much fewer steps.…”

“…[36,37] Transitional metal complexes have been greatly studied in the catalyst field due to the solubility properties of transition metal complexes in the aqueous phase and also in drug discovery in accordance to their cytotoxic, antimicrobial and antitumor properties. [9,11,32,38] There is not much information on zirconium (IV) complexes in the synthesis of benzo[a]benzo [6,7]chromeno[2,3-c]phenazine derivatives. Therefore, in this work, the guanine complex of zirconium ions supported on modified MCM-41 nanoparticles has been synthesized and characterized by FT-IR, Raman, XRD, BET, TGA, EDX, ICP, AAS, X-Ray mapping, SEM and TEM techniques.…”

“…According to the structure of guanine, in several models of metal complexes, the metal ions bind to the guanine ring through carbonyl oxygen O (6) and/or imidazolyl nitrogen, N (7) and/or N (1) position of guanine). [38] Afterwards, they are used as an efficient catalyst for the clean and facile one-pot domino synthesis of spiro[benzo[a]benzo [6,7] phenazine and bis (pyrazolyl)methane derivatives via the Knoevenagel condensation-Michael additioncyclization reactions of 2-hydroxy-1,4-naphthoquinone (lawsone), benzene-1,2-diamine and carbonyl compounds (aldehydes and ninhydrin and isatin as cyclic ketones) and the Knoevenagel condensation-Michael addition reactions of 3-Methyl-1-phenyl-5-pyrazolone with aryl aldehydes. The main advantages of this synthesis include simple workup, reusability of the catalyst, easy recovery and fewer reaction steps without the intermediates separation.…”