Diversity-oriented four-component synthesis of solid state luminescent difluoro oxazaborinines

(Hetero)aroyl chlorides, alkynes, anilines, and BF3 diethyl etherate are reacted in an alkynylation-amination-cyclization one-pot process to give trisubstituted difluoro oxazaborinines in moderate to very good yield in the sense of a consecutive four-component synthesis. The obtained title compounds are intensely fluorescent with bluish to yellow color, however, only in the solid state. Photophysical measurements, physical organic correlation studies, and DFT and TD DFT calculations are employed to rationalize the substituent effects on the dominant chromophores, which is oriented along the dipole axis spanning from the (hetero)aroyl substituent to the aniline moiety.