A review on transition-metal mediated synthesis of quinolines

Abstract

Quinoline is one of the important class of heterocyclic compounds which have gained considerable importance because of its high pharmaceutical efficacy and broad range of biological activities such as anticancer, anti-malarial, anti-microbial and anti-asthmatic. As a consequence, the desire for new versatile and efficient route for the synthesis of quinoline scaffolds remains an active and growing area of interest both in academia and industry. However, developments of transition-metal catalyzed synthetic methods have witnessed a dominant position over the past few years for the synthesis of diverse range of complex heterocyclics containing quinoline scaffolds. This review specifically provides an overview of the literature available on the transitionmetal catalyzed synthetic methodologies for the synthesis of polysubstituted quinoline derivatives.

Phosphine Ligand‐Free Ruthenium Complexes as Efficient Catalysts for the Synthesis of Quinolines and Pyridines by Acceptorless Dehydrogenative Coupling Reactions

“…[1][2][3][4][5] Numerous synthetic protocols for the quinoline nucleus have been reported, including the Skraup, Comps, Conrad-Limpach, Gould-Jacobs, Doebner-von Miller and Povarov reactions. [6][7][8][9][10][11][12] Pyridine derivatives can be synthesized by transition metal catalyzed cycloaddition reactions. [13][14][15][16][17][18][19][20][21][22] However, harsh reaction conditions, low stereoselectivity, multiple steps and low yields limit the general applicability of these methods.…”

Recent synthetic efforts in the preparation of 2-(3,4)-alkenyl (aryl) quinoline molecules towards anti-kinetoplastid agents

“…The most popular metal catalysts used in the extensions of these traditional quinoline syntheses are iron, gold, silver, and copper. [147][148][149][150][151][152] A 3 -type Povarov reactions of primary aromatic amine 49, aldehyde 15 and alkyne 71 (A 3 synthesis) to give 2,4-diphenylquinolines 90 (Scheme 26) have become very popular in these recent years can provide a good functional group diversity. These transformations were performed in the presence of Cu(OTf) 2 (5 mol%) 153 or Zn(OTf) 2 (5 mol%) 154 without any solvents.…”

Heck Reactions of Acrolein or Enones and Aryl Bromides – Synthesis of 3‐Aryl Propenals or Propenones and Consecutive Application in Multicomponent Pyrazole Syntheses

“…In particular, cinnamic aldehyde derivatives find widespread application in food,[3a] cosmetic and perfume, agrochemical and pharmaceutical industry. As Michael systems α,β‐unsaturated ketones and aldehydes are valuable three‐carbon building blocks in syntheses of five‐, six‐ and seven‐membered nitrogen heterocycles, such as pyrazoles, quinolines, or pyridines . In addition, they have recently received considerable attention as substrates in organocatalysis …”