Robust synthesis of NIR-emissive P-rhodamine fluorophores

Abstract

A library of P-rhodamines was prepared via a new robust sequence that creates the core heterocycle by addition of diaryllithium reagents to esters. The first SAR study for P-rhodamines shows that they are NIR-emissive and highly bright fluorophores.

Rhodamine Fluorophores for STED Super‐Resolution Biological Imaging

“…The development of facile synthetic strategy will further explore its potential for super-resolution fluorescence imaging. [20,73] Tuning the substitution on 3-and 6-amino groups can adjust the lipophilicity of rhodamines, making them either more lipophilic for membrane staining or more hydrophilic for better membrane penetration. The alkylamino group in typical rhodamine can undergo step-wise photo-oxidative dealkylation, leading to the problem of photo-stability.…”

“…Besides Si-rhodamine, Hell et al reported a series of rhodamine derivatives by replacing xanthene oxygen with other atoms, such as carbon and germanium (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21), Figure 4 and Table 2). [21a,30] The quantum yields are significantly affected by atom changes, for example, carbo-rhodamine (C-rhodamine) has the lowest quantum yields when compared with Sirhodamine and normal rhodamines (O-rhodamine).…”

Late-stage functionalisation of alkyne-modified phospha-xanthene dyes: lysosomal imaging using an off–on–off type of pH probe

“…1a, which have been developed as a new class of NIR dyes, are potentially suitable candidates. [20][21][22][23][24][25][26][27][28][29] These dyes replace the endocyclic oxygen atom of the classical xanthene scaffold with an electron-withdrawing phosphine oxide (>P(=O)R) moiety. The phospha-xanthene dyes have been used as NIR-labelling reagents in optical imaging both in vitro and in vivo.…”

Design, Synthesis, and Evaluation of Near-Infrared Fluorescent Molecules Based on 4H-1-Benzopyran Core

“…Therefore, through the modification of the conjugated skeleton or terminal substituents, different application requirements of fluorescent molecules could be met [5]. Currently, D-A or D-A-D fluorescent molecules including rhodamine, fluorescein and BODIPY [6][7][8][9][10][11] have several main applications, such as detecting diseases (cancers and Alzheimer) [12,13], imaging live-cell fluorescence [14], and being fluorescent molecular switches [15]. In this work, we laid focus on the coumarins [16], and explored the changes in the fluorescence properties of a series of compounds when the electron donor and acceptor structure are changed.…”