Facile One-Pot Friedlander Synthesis of Functionalized Quinolines using Graphene Oxide Carbocatalyst

Abstract

Background: Quinolines represent an important class of bioactive molecules which are present in various synthetic drugs, biologically active natural compounds and pharmaceuticals. Quinolines find their potential applications in various chemical and biomedical fields. Thereby, the demand for more efficient and simple methodologies for the synthesis of quinolines is growing rapidly. </P><P> Objective: The green one-pot Friedlander Synthesis of Functionalized Quinolines has been demonstrated by using graphene oxide as a carbocatalyst. </P><P> Method: The graphene oxide catalyzed condensation reaction of 2–aminoaryl carbonyl compounds with different cyclic/ acyclic/ aromatic carbonyl compounds in methanol at 70°C affords different quinoline derivatives. </P><P> Results: The reaction has been examined in different protic and aprotic solvents and the best yield of quinoline is observed in methanol at 70°C. Conclusion: The present method of quinoline synthesis offers various advantages over other reported methods such as short reaction time, high yield of product, recycling of catalyst and simple separation procedure. The graphene oxide carbocatalyst can be easily recovered from the reaction mixture by centrifugation and then can be reused several times without any significant loss in its activity.

A simple, safe, eco‐friendly, and unique synthesis of hexahydro‐quinolines employing Fe3O4‐MWCNT@MnO2 as a reusable catalyst

“…Recent reports have described the synthesis of many quinoline analogues utilizing a range of catalysts, including phosphoric acid, GO, Fe 3 O 4 @SiO 2 /ISN/Cu (II), SiO 2 /H 2 SO 4 , [GrBen-zImi]SO 3 H, sulfated polyborate, Mn (CO) 5 Br, and PANEOSF. [34][35][36][37][38][39][40][41][42][43] Numerous strategies that are discussed offer benefits in themselves. Nevertheless, most of these techniques need laborious work-up procedures, expensive catalysts, convoluted stages, and extended reflux heating in organic solvents.…”

“…Although there are several techniques to build the structural core of quinolines, Friedländer annulation remains one of the most convenient and attractive methods for generating poly‐substituted quinolines. Recent reports have described the synthesis of many quinoline analogues utilizing a range of catalysts, including phosphoric acid, GO, Fe 3 O 4 @SiO 2 /ISN/Cu (II), SiO 2 /H 2 SO 4 , [GrBenzImi]SO 3 H, sulfated polyborate, Mn (CO) 5 Br, and PANEOSF 34–43 . Numerous strategies that are discussed offer benefits in themselves.…”

Synthesis of multiple quinoline derivatives using novel ionic liquid-based nano-magnetic catalyst (MNPs@SiO2-Pr-AP-tribromide)

“…Quinoline synthesis in this method, which involves a condensation followed by a cyclodehydration between 2-aminoarylketones and α-methylene ketones, is catalyzed by both acids and bases [36,37]. In recent years, metal-organic framework (MOFs) catalysts such as UiO-66(Hf) [38] and Zn-MOF [39], chiral phosphoric acid (CPA) [40], Solid SiO 2 /H 2 SO 4 [41], ionic liquid ImBuSO 3 H [42], Brønsted acid and Lewis acid [43], [GrBenzImi]SO 3 H [33], graphene oxide carbocatalyst [44], Fe 3 O 4 @SiO 2 / ISN/Cu(II) [45], DDBSA@MNP [46], microwave irradiation [47,48], and sulfated polyborate [49]. Organosilane [50], Mn(CO) 5 Br [51], and PAN EOS F [52] have also been utilized to be effective for this synthesis.…”

Gold-carbonaceous materials based heterostructures for gas sensing applications

“…8 The development of various nanomaterials is gaining towering height due to their unique properties and wide applications. [9][10][11][12][13][14][15][16] Recently, carbonaceous materials such as graphene, carbon nanotubes (CNTs), graphitic carbon nitride have attracted enormous attention due to their excellent physical, chemical properties, high specic surface area, etc. Furthermore, carbon nanomaterials' mechanical properties increase their suitability to integrate them into exible sensor devices.…”