Catalytic Enantioselective Difluoroalkylation of Aldehydes

Copper‐catalyzed bond scission of pentafluorobutane‐1,3‐diones generates difluoroenolates that react with aldehydes to give a wide range of chiral α,α‐difluoro‐β‐hydroxy ketones within a few hours in up to 99 % yield and 92 %  ee. The synthetic utility of this reaction is demonstrated with the stereoselective synthesis of a chiral anti ‐1,3‐diol exhibiting a central difluoromethylene unit and efficient conversion to a 2,2‐difluoro‐3‐hydroxy carboxylic acid.