Cyanine Dyes Containing Quinoline Moieties: History, Synthesis, Optical Properties, and Applications

Abstract

Cyanine dyes carrying quinoline moieties are an important class of organic molecules that are of great interest for applications in many fields like medicine, pharmacology, and engineering. Despite their exceptional properties, such as stability, high molar extinction coefficients, and high pH‐sensitivity, this class of dyes has been less analyzed and reviewed in the last few decades. Therefore, this review article focuses on discussing the history of quinoline compounds, various synthetic routes to prepare quinolinium salts and symmetrical and asymmetrical mono‐, di‐, tri‐, penta‐ and heptamethine cyanine dyes, containing quinoline moieties, together with their optical properties and applications as photosensitizers in photodynamic therapy, probes in biomolecules for labeling of nucleic acids, as well as imaging agents.

Near‐Infrared Fluorophores Based on Heptamethine Cyanine Dyes: From Their Synthesis and Photophysical Properties to Recent Optical Sensing and Bioimaging Applications

“…Here, the biological application trends and existing limitations of fluorescent dyes were properly discussed [22] . A more comprehensive discussion about their synthesis, optical properties, and applications was presented by Henary and Ilina; [23] however, they only focused on cyanines containing quinoline moieties. In this context, this review discusses several aspects of the synthesis of heptamethine cyanine dyes and the chemical modification of their structures in terms of their recent photophysical applications in bioimaging.…”

“…tions was presented by Henary and Ilina; [23] however, they only focused on cyanines containing quinoline moieties. In this context, this review discusses several aspects of the synthesis of heptamethine cyanine dyes and the chemical modification of their structures in terms of their recent photophysical applications in bioimaging.…”

Solid-Phase Synthesis of Asymmetric Cyanine Dyes

“…However, an additional classification is commonly reported based on the chemical structure of the groups bearing the nitrogen atoms (Figure 1). Cyanines without any terminal heterocyclic groups are named streptocyanines, those with only one terminal heterocycle are hemicyanines and, those with two heterocycles at the chain edges are called closed chain cyanines [25][26]. In the latter family, a further subclassification is used by the nature of the heterocyclic structures such as indole, benzoindole, benzoxazole, benzothiazole, benzoselenazole, quinaldine and lepidine (Figure 3).…”

An aza-Diels–Alder approach to chlorinated quinolines, benzoquinolines, and polybenzoquinolines

“…Quinolines and quinoline-containing macromolecules have been studied for over a century because of their desirable biological activities and favourable combinations of materials properties. [1][2][3][4][5][6][7][8][9][10][11][12] In particular, quinoline-containing molecules are famous for their strong antimalarial activity and for their critical roles in anticancer drug development. [1][2][3][4][5][6] Moreover, quinoline-derived macromolecules have found applications as active materials in organic electronic devices, stable heatresistant coatings in packaging, and uorescent probes in various sensing schemes.…”

“…[1][2][3][4][5][6] Moreover, quinoline-derived macromolecules have found applications as active materials in organic electronic devices, stable heatresistant coatings in packaging, and uorescent probes in various sensing schemes. [7][8][9][10][11][12][13][14][15][16][17][18] As such, substantial effort has focused on the preparation of quinolines and quinoline-based polymers, with the former oen synthesized via the Combes, Conrad-Limpach, Skraup, Doebner-Miller, Friedländer, Ptzinger, or Povarov reactions [19][20][21][22][23][24][25] and the latter primarily synthesized via Suzuki, Sonogashira, oxidative coupling, Friedländer, or Povarov polymerization methodologies. 7,8,10,[26][27][28][29][30][31][32][33][34][35] Given the importance and value of quinolines and their derivatives, there exists powerful motivation for the continued improvement and renement of the aforementioned synthetic strategies.…”