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A proficient and meticulously designed diasterioselective, multicomponent, one-pot synthesis of densely substituted piperidine derivatives has been elaborated using polystyrene sulfonic acid catalyst via tandem reactions of 1,3-dicarbonyl compounds, aromatic aldehydes and various amines. Shorter reaction times, high yields and a polymer-supported inexpensive catalyst are the noteworthy aspects of the scaffold. Graphical Abstract: [ABSTRACT FROM AUTHOR]

A series of novel 18-crown-6 ether functionalized bis-benzimidazole derivatives ( 3a- g) have been synthesized by reacting various substituted ortho-phenylene diamines and pyridine diamines with 4,4′-diformyl dibenzo-18-crown-6 ether ( 1). The required starting material 4,4′-diformyl dibenzo-18-crown-6 ether ( 1) was prepared by Duff formylation method. All synthesized novel molecules have been identified on the basis of infrared (IR), H nuclear magnetic resonance (NMR), C NMR, mass spectroscopy (MS), and elemental analyses. The title compounds ( 3a- g) were tested for antifungal activity against Aspergillus niger, Trichothecium sp., Rhizopus sp., and Sclerotium rolfsii fungi species using agar well diffusion method, showing mild to good results. Graphical abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The quest to develop an environmentally friendly, sustainable protocol for immensely bioactive spirooxindole derivatives has encouraged to explore oxalic acid dihydrate: proline low transition temperature mixture as a new designer solvent for the said synthesis at room temperature. It has been successfully applied for the three component reaction of isatin, malononitrile or ethyl cyanoacetate and 1,3-dicarbonyl compounds for the first time. Moderate to good yield of the products, shorter reaction time, energy efficiency, chromatography-free purification process, recyclability and high atom economy are the captivating feature of this protocol which will find applications in multi-component, diversity-oriented synthesis. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

An innovatively designed novel crown ether functionalized imidazolium-based reusable acidic ionic liquid [crown ether MIm] [HSO] has been efficiently implemented for the synthesis of pyrazole derivatives using various substituted enaminones, hydrazine hydrate and phenyl hydrazine under solvent-free conditions. Structural novelty and task efficiency of the catalyst, high yields of desired products, greener approach attributing high atom economy and solvent-free conditions render this protocol suitable to cope with the current demand in contemporary organic chemistry. The inventive idea of utilizing crown ether functionalized ionic liquid as a catalyst was for the first time demonstrated in this protocol. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

(±)-Camphor-10-sulfonic acid is used for the synthesis of triazolo[1,2-a]indazole-triones and spiro triazolo[1,2-a]indazole-tetraones by condensation reaction of dimedone, urazole and aromatic aldehydes or isatin. The noteworthy aspects of this new method are high yields, high atom efficiency, use of non-toxic solvent, mild conditions, simple workup and synthesis of complex molecules using an eco-friendly, inexpensive catalyst. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstracts: A novel, highly efficient and recyclable Brønsted acidic ionic liquid ([CMIM][CFCOO]) has been successfully implemented for the synthesis of acridinediones in aqueous media. Recyclability of novel catalyst, high yields, use of environmentally benign aqueous media as solvent, simple product isolation, high atom economy and sidestep to column chromatography are the noteworthy features of this protocol. This protocol is competent for producing wide library of acridinediones in good to excellent yields. Furthermore, molecular structure and relative stereochemistry of 4c and 4s derivatives were confirmed by single-crystal X-ray diffraction. Graphical Abstract: [InlineMediaObject not available: see fulltext.] [ABSTRACT FROM AUTHOR]