Poly(vinylpyrrolidinium) perchlorate as a new and efficient catalyst for the promotion of the synthesis of polyhydroquinoline derivatives via Hantzsch condensation

Abstract

A green approach for the promotion of the synthesis of Hantzsch products using poly(vinylpyrrolidinium) perchlorate {[PVPH]ClO 4 } as a new modified polymeric catalyst in the absence of solvent is reported. The title catalyst is easily prepared and characterized using a variety of techniques including infrared spectra, X-ray diffraction, thermal gravimetric analysis, scanning electron microscopy, pH analysis, and Hammett acidity function. Some of the advantages of this novel synthetic method are: easy preparation of the catalyst, short reaction times, high to excellent yields of the products, simple and easy work-up procedure, and reusability of the catalyst.

First Asymmetric Synthesis of Passerini‐Type Condensation Products in Water Using Pregabalin: A Chiral Amino Acid for the Efficient Asymmetric Induction

“…In continuation of our previous studies on the introduction of new catalysts for the promotion of multi‐component reactions [44–48] and specially bio‐organic ones, [49–51] in this investigation concurrent generation of carboxylic acids from the aerobic oxidation of aldehydes leading to α ‐acyloxycarboxamides with an stereogenic center and considerable ee by the supporting role of Pregabalin as an efficient reagent under the auxiliary of water is reported. It should be noted that although the role of amino acids in reaction with isocyanide and aldehydes was studied in the Ugi's reaction, [52–53] in this work we showed that by changing of the solvent and temperature the same reaction can lead to the production of the asymmetric Passerini's products (Scheme 3).…”

2,4-Dioxo-1,3-diazaspiro[4,5]decane-3-sulfonic Acid as a Novel Solid Phase Halogen-free Acid Catalyst: Preparation, Characterization and Evaluation

“…4c) was achieved efficiently from the benzaldehyde derivatives (1 mmol), dimedone (1 mmol) and ethyl acetoacetate (1 mmol) in the presence of NSCH at 80°C under solvent-free condition. The results are listed in Table 2 (entries [18][19][20][21][22]. Two alternative reaction pathways to achieve this outcome are shown in Fig.…”

“…[12][13][14] Xanthene, chromene and hydroquinoline derivatives are important organic compounds with a wide range of applicability and biological activity. [15][16][17][18][19][20] Although some synthetic methodologies have been reported for each class of these compounds in the literature, [21][22][23][24][25][26][27][28][29][30][31][32] each with their own advantages, many of them suffer from some disadvantages. The use of homogeneous acid catalysts may result in some difficulties with product separation and purification, low yield, long reaction time, use of toxic organic solvents and harsh reaction procedures.…”

A New Supported Manganese-Based Coordination Complex as a Nano-Catalyst for the Synthesis of Indazolophthalazinetriones and Investigation of Its Antibacterial Activity

“…Mosaddegh's group succeeded in synthesizing phthalazinetriones derivatives through a rapid, one-pot, four-component route by using Ce(SO 4 ) 2 4H 2 O at 125 • C and under solvent-free conditions [23]. However, some methods experienced some limitations such as tedious workup procedures, using corrosive catalysts, low product yields, long reaction times, formation of side products, and difficulties in recovery of catalysts [24].…”