Design of novel meso-CF3-BODIPY dyes with isoxazole substituents

The two approaches for the synthesis of meso-CF3 substituted BODIPY dyes bearing isoxazole substituents at the position 3 of boradiazaindacene core have been developed. The key stages of the approaches are cycloaddition of hydroxylamine to the triple bond of available ethynyldipyrromethanes (1) and synthesis of isoxazoles from ethynylpyrrole and their further condensation with 2,2,2-trifluoro-1-(pyrrol-2-yl)-1-ethanols (2). The novel BODIPY dyes exhibit prospective optical features and fluorescence in the 611-646 nm with high (up to 0.94) quantum yield. Spectroscopic results have been rationalized with quantum mechanics calculation.