Synthesis of Rhodamines and Rosamines Using 3,6-Difluoroxanthone as a Common Intermediate

Abstract

Rhodamines and structurally similar rosamines are some of the most highly utilized tools for molecular imaging experiments. We report a general and high-yielding route to produce 18 examples of rhodamines and rosamines, including tetramethylrhodamine, rhodamine B, and Janelia Fluor 549, from a single xanthone intermediate, 3,6-difluoroxanthone. Spectroscopic studies revealed trends in fluorophore efficiency based on substitution patterns at the 3′-, 6′-, and 9′-positions, providing insights to aid future designs of rhodamines/rosamines.

Synthesis of a fluorinated pyronin that enables blue light to rapidly depolarize mitochondria

“…26,27 As shown in Scheme 1, pyronins 3, 4 and 8 were synthesized from the previously reported 28 2,7-difluoroxanthone (7), whereas the azetidine analogues 5 and 6 were prepared from the known precursors 9-12. 28,29 Pyronin B (2) and its structurally similar N,N-dimethyl analogue (pyronin Y) are highly fluorescent. 30 To characterize the optical properties of analogues 2-8, we obtained absorbance and emission spectra in ethanol (Fig.…”

“…26,27 As shown in Scheme 1, pyronins 3 , 4 and 8 were synthesized from the previously reported 28 2,7-difluoroxanthone ( 7 ), whereas the azetidine analogues 5 and 6 were prepared from the known precursors 9–12 . 28,29…”

Hydrophobic Carbon Dots Derived from Organic Pollutants and Applications in NIR Anticounterfeiting and Bioimaging

“…Here, we synthesized a novel HNCD using organic pollutant as a single precursor via a one-pot solvothermal method. Rhodamine B is selected as a model due to its rigid coplanar structure and single carboxyl group, , which is expected to enhance the photoluminescence properties and extend the fluorescent emission. , The morphology feature, chemical structure, and fluorescent performance of the as-prepared HNCDs have been comprehensively analyzed. The HNCDs exhibited excellent solvent-dependent and tunable fluorescence emission properties over a wide range of excitation wavelengths.…”

Functionalization of Rhodamine Platforms with 3-Hydroxy-4-pyridinone Chelating Units and Its Fluorescence Behavior towards Fe(III)

“…Rosamines are rhodamine analogues that lack the carboxylic acid group at the ortho position of the phenyl ring, and therefore are unable to participate in spirolactone-quinoid equilibria. Rosamines are often considered advantageous over rhodamines as they exhibit very attractive photophysical properties and are usually easier to synthesize and to purify [ 11 , 12 , 13 , 14 ].…”