Facial Access to 2,2-Difluoro-2,3-dihydrofuran Skeleton without Extra Additive: DMF-Promoted Difluorocarbene Formation of ClCF2CO2Na



The practical and facile difluorocarbene-triggered cycloaddition reaction of enaminones was developed, that delivered 2,2-difluoro-2,3-dihydrofurans with broad substrates scope. Notably, the reaction proceeded smoothly without any extra additive. The readily available sodium chlorodifluoroacetate (ClCF2CO2Na, SCDA) played as difluorocarbene precursor in this transformation through DMF-promotion. Moreover, it is proved that the 2,2-difluoro- 2,3-dihydrofuran derivatives exposed potential antiproliferative activity against human tumour cells HeLa, MCF7 and HepG2.