A one‐pot green synthesis of 2‐amino‐4H‐benzo[h]chromenes catalyzed by a dioxomolybdenum Schiff base complex supported on magnetic nanoparticles as an efficient and recyclable nanocatalyst

Abstract

In this work, catalytic performance of a molybdenum Schiff base complex‐supported magnetic support as a nanocatalyst was evaluated for the preparation of 2‐amino‐4H‐benzo[h]chromenes through one‐pot, three component reactions of 1‐naphthol, various aldehydes, and malononitrile under solvent‐free conditions. A promising greener and eco‐friendly method with a short reaction time, high yield of products, and simple work‐up procedure was achieved. The nanocatalyst could be easily separated and regenerated from reaction media by an external magnet and reused at least seven consecutive times with small drops in its catalytic performance.

Solvent‐free synthesis of compounds containing chromene core catalyzed by novel Brønsted acidic ionic liquids‐ClO4

“…Although most of the previously reported catalysts [ 30–38 ] have proper ability to advance the reactions with good yields, some of them require harsh conditions, such as high reaction temperatures or long times, and others suffer from a problem in separating the catalyst from the reaction mixture and nonrecyclable catalyst. The features of this method, which makes it more preferable than other reported methods, are mild reaction conditions, environmentally benign, easy recovery of BAILs‐ClO 4 catalyst, reuse of the catalyst for six consecutive times without loss of catalyst performance, high yields of 2‐amino‐4 H ‐chromene derivative products, and short reaction times.…”

“…Due to the importance of the functionalized 4 H ‐chromenes, especially in medicinal chemistry, several synthetic protocols have been reported in the literature; that most of them suffer from some disadvantages such as multiple synthetic steps, boring reaction conditions, and expensive reagents. [ 30–38 ]…”

Ionic liquid‐assisted synthesis of 2‐amino‐3‐cyano‐4H‐chromenes: A sustainable overview

“…Different kinds of catalytic reagents (metal-based or metal-free basic and acidic catalysts, heterogeneous catalysts, phase transfer catalysts) have been employed for the multicomponent reaction (MCR) to produce the chromene derivatives (Scheme 1). [79][80][81][82][83][84][85][86][87][88][89][90][91][92] In this regard, most of these techniques display some major drawbacks such as the use of toxic solvents, unexpected conditions, product separation, and purification. Above all, the catalytic composites are not considered eco-friendly and some difficulties are found during the recyclability of the catalyst.…”

Copper Schiff base complex immobilized on magnetic graphene oxide: Efficient heterogeneous nanocatalyst for treating environmental pollutants and synthesis of chromenes

“…The importance of MCRs in chemistry is because of their simplicity, selectivity, high productivity, reduced number of synthesis steps and so reaction time, low energy consumption, and waste production. [30,31] Among the heterocyclic compounds, 4H-pyran and its derivatives including six-membered ring heterocycles with oxygen have attracted considerable attention due to their diverse properties. [32] Following our previous efforts for the development of green catalytic protocols for various synthetic transformations [17] and regarding the principles of green chemistry, in this research, we synthesized of a copper (II) Schiff base complex supported on magnetic GO (GO/Fe 3 O 4 /CuL) as an efficient, heterogeneous, and recyclable nanocatalyst for the onepot synthesis of 2-amino-4H-benzo[h]chromene derivatives in the presence of malononitrile and 1-naphthol with different aldehydes.…”