ZrO₂/SO₄²⁻/Cu as a Multifunctional, Durable, Efficient, and Heterogeneous Recoverable Inorgano‐Nanocatalyst for the Green Preparation of Quinolines

Abstract

An efficient, simple and highly versatile method for the preparation of quinoline derivatives was developed via the Friedländer annulation reaction of 2‐aminoarylketones with carbonyl compounds using copper‐incorporated sulfated zirconium oxide (ZrO2/SO42−/Cu) as a heterogeneous recyclable nanocatalyst. The catalyst was characterized by FTIR, TG‐DTG, XRD, EDX, FE‐SEM and TEM analyses. Surface acidity of the catalyst was measured by pyridine adsorption followed by FTIR spectroscopy. The catalyst contains various Lewis‐ and Brønsted acid sites, which along with the incorporated copper, provides high to excellent yields for all compounds in water as a green solvent at room temperature for short reaction times. The catalyst could be efficiently reused for several runs without any appreciable loss of activity. In addition, the scalability of the process was investigated in this work. Finally, a plausible reaction mechanism was suggested for this transformation.

Synthesis, Optical and Electrochemical Properties of Isomeric Dibenzophenanthroline Derivatives

“…Compound 3 has been previously made in 86% yield by solvent‐free microwave‐assisted Friedländer condensation of an acridone with 1 and concentrated sulfuric acid [14a] . The acridone has been reportedly made by condensation of 1 with 1,3‐cyclohexadione in 99–100% yield, [14b— — d] producing an overall yield of 3 from 1 in 2 steps of 85–86% yield. Our synthesis is shorter and uses milder conditions, but has a lower yield (40%).…”

Recent Advances in Green Synthesis of Functionalized Quinolines of Medicinal Impact (2018‐Present)

“…Nasseri et al reported synthesis of Quinoline derivatives 192 via Friedländer annulation reaction of 2-aminoarylketones 57 and carbonyl compounds 191 using copper-incorporated sulfated zirconium oxide (ZrO 2 /SO 4 2À /Cu) as a heterogeneous recyclable nanocatalyst (Scheme 52). [92] The catalyst contained the Lewis and Brønsted acid sites with incorporated copper which resulted in excellent yields of products in water at room temperature. The recyclability of the catalyst was also good upto many times without much loss of activity.…”

Sulfated zirconium oxide-decorated magnetite KCC-1 as a durable and recyclable adsorbent for the efficient removal of asphaltene from crude oil

“…Sulfated zirconium oxide was prepared according to a previously reported procedure. 23,24 First, to a solution of 2.3 g of ZrCl 4 (as a precursor) in distilled water (10.0 mL), 10.0 mL of 1.0 N ammonia solution was added dropwise during a span of 30 min to the solution until the solution pH was adjusted to 11.0. The milky solution was aged for a day at room temperature.…”