Preparation of α,α-difluoromethylene functionalized sulfones

Sulfination of bromodifluoroacetate or acetamide 1 with sodium dithionite gives the corresponding sulfinates 2a , and 2b , respectively, which upon cuprous bromidc catalyzed allylation afford the allylsulfonyl-difluoroacetate and acetamides. Phenyl- or alkylsulfonyldifluoroacetates and acetamides can be readily prepared from reaction of 1 with thiolates, followed by oxidation with hydrogen peroxide.