Facile access to gem-difluorocyclopropanes via an N-heterocyclic carbene-catalyzed radical relay/cyclization strategy

N -Heterocyclic carbene-catalyzed difluorocyclopropanation of alkenes with aldehydes and CF 2 Br 2 for a facile and efficacious synthesis of a new class of functionalized gem -difluorocyclopropanes bearing acyl groups was developed.