The Sonogashira reaction as a new method for the modification of borated analogues of the green fluorescence protein chromophore

The Sonogashira reaction was used for modifications of borated green fluorescence protein chromophore derivatives, 4-(2-(difluoroboryl)benzylidene)-1 H -imidazol-5(4 H )-ones, for the development of new fluorescent dyes. The derivatives bearing an acetylene fragment and a difluoroboryl group were obtained in high yields. The modification resulted in a significant bathochromic shift of the absorption and emission maxima and is a promising method for the development of new fluorescent dyes.