Ultrasound-assisted one-pot multi-component synthesis of 2-pyrrolidinon-3-olates catalyzed by Co3O4@SiO2 core–shell nanocomposite

2-pyrrolidinon-3-olates were synthesized via one-pot four-component reaction of 2-aminobenzothiazole, aromatic aldehydes, dimethyl acetylenedicarboxylate and morpholine/piperidine in the presence of Co3O4@SiO2 core–shell nanocomposite as catalyst under ultrasound irradiation. The protocol offers several such advantages as high yields, short reaction time and mild reaction conditions with reusability of the catalyst. The core–shell nanocomposite was also prepared using ultrasound irradiation and the structure and magnetic properties were fully characterized by TEM, FE-SEM, XRD, EDX, FT-IR and VSM analysis

Fe₃O₄@SiO₂–NH₂ core-shell nanocomposite as an efficient and green catalyst for the multi-component synthesis of highly substituted chromeno[2,3-b]pyridines in aqueous ethanol media

<div><p>ABSTRACT</p><p>An efficient and green approach for synthesizing chromeno[2,3-b]pyridine derivatives through one-pot three-component reactions of salicylaldehydes, thiols, and malononitrile has been developed by Fe₃O₄@SiO₂–NH₂ nanocatalyst in aqueous ethanol media under reflux conditions. The present procedure provides several advantages such as environmentally benign, straightforward, excellent yields, short reaction times, cost-effective, good recyclability, little catalyst loading, and facile catalyst separation for the preparation of chromeno[2,3-b]pyridines as important privileged medicinal scaffold. In addition, aminopropyl-coated Fe₃O₄@SiO₂ nanoparticles were fully characterized by scanning electron microscopy, X-ray diffraction, energy dispersive analysis of X-ray, vibrating sample magnetometer, and FT-IR analysis.</p></div

Multi-component synthesis of spiro[diindeno[1,2-b:2′,1′-e]pyridine-11,3′-indoline]-triones using zinc terephthalate metal-organic frameworks

<p>The present article describes an efficient one-pot method for the preparation of spiro[diindeno[1,2-b:2′,1′-e]pyridine-11,3′-indoline]-trione derivatives from a three-component condensation reaction of 1,3-indandione, aromatic amines and isatins in the presence of a zinc terephthalate metal-organic framework Zn (BDC) MOF as the catalyst under solvent-free conditions. High yields, short reaction times, simple workup and environmentally benign procedure are advantages of this protocol. The Zn (BDC) MOF catalyst can be recovered and reused several times without loss of activity. The catalyst was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infra red, X-ray powder diffraction and thermal gravimetric analysis.</p