Pyridone fused boron-dipyrromethenes: synthesis and properties

In this paper a general procedure for the introduction of pyridone moiety was developed, using a Friedländer reaction, for post-modification of ready-made BODIPY core, from which three pyridone-fused BODIPYs 1, 2 and 3 were generated. This method is complementary to the classical method for obtaining aromatic ring-fused BODIPYs, which begins with the condensation of the corresponding aromatic ring-fused pyrroles. These pyridone-fused BODIPYs are distinctive, possessing favorable photophysical characteristics with strong absorption, high bright orange fluorescence and easy reduction due to the electron-withdrawing effect of the fused pyridone moiety. More important, these BODIPYs bear reactive functions which are applicable in proteins labeling by bioorthogonal chemical reactions.