Preparation and reaction of 2-chloro-3,3-difluorocyclopropenylzinc reagent

Abstract

2-Chloro-3,3-difluorocyclopropenylzinc reagent 1, readily prepared by the direct reaction of 1-chloro-3,3-difluoro-2-iodocyclopropene with zinc powder in dimethylformamide–hexamethylphosphoric triamide co-solvent, exhibits excellent stability at room temperature in the absence of oxygen and/or moisture. The reaction of this zinc reagent with a variety of acyl and alkyl halides is found to be catalysed by copper(I) bromide and represents a convenient route to the synthesis of previously inaccessible substituted 3,3-difluorocyclopropenes.