LAUSR

Abstract This short study reports firstly the synthesis of a new series of six 1-substituted 6-((4,4,4-trihalo-3-oxo-alk-1-en-1-yl)amino)-2H-chromen-2-ones (4 and 5) and three 4- substituted 2,2-difluoro-3-(2-oxo-2H-chromen-6-yl)-6-(trichloromethyl)-2H-1,3,2-oxazaborinin-3-ium-2-uides (7), in which the selected 1- and 4-substituents are Me, Ph, and thien-2-yl. Both series (4 and 5) were synthesized from the reaction of 6-aminecoumarin (3) with (Z)-1,1,1-trihaloalk-3-en-2-ones (1 and 2), at 50–95 % yields. Subsequently, reactions of the coumarins 4 and 5 with boron (BF3·OEt2) gave only the corresponding 6-trichlorometylated heterocycles (7), at 65–78 % yields. Absorption and emission properties were investigated for the new coumarin derivatives. The results for UV–vis, emission fluorescence, quantum yield, and Stokes shift analysis indicated important relationships between the β-enaminone skeletons and their substituents.