Copper-Catalyzed Bromodifluoroacetylation of Alkenes with Ethyl Bromodifluoroacetate.

A Cu-catalyzed regioselective bromodifluoroacetylation of alkenes, using ethyl bromodifluoroacetate (BrCF2CO2Et) as a difluoroacetylating reagent, has been disclosed. The reaction proceeds under mild conditions, and possible byproducts generated from hydrodifluoroacetylation and/or direct alkenyl C-H difluoroacetylation are not observed. Mechanistic studies confirm that the atom transfer radical addition (ATRA) process is involved in this alkene difunctionalization reaction.