Fluorescent 2‑(Pyridin-2-yl)vinyl Pyridine Dyes and Their Thermocontrolled Release

The
generation of unique thermosensitive fluorescent dyes via heteroaromatic
Heck cross-coupling and N-pyridin-2-yl nucleophilic
substitution was described. To demonstrate thermosensitive properties,
the precursor was converted into carbonates or phosphates and heated
at various temperatures and for various time periods. Significant
changes in the fluorescence intensity and emission wavelengths, between
carbonates and the cyclic product, were observed, and it was proved
that the dyes may serve as removable fluorescent labels with large
Stokes shifts (>80 nm). The application of thermosensitive fluorescent
dyes in oligonucleotide labeling has been demonstrated.