General method for the preparation of β,β-difluoroacrylates using BrF3

Various esters were reacted with base, carbon disulfide, and methyl iodide, producing 2-carboalkoxy1,1-bis(methyl sulfide)-1-alkenes (2). The reaction of 2 with BrF3, followed by oxidation with HOF-CH3CN gave the bromodifluorosulfonyl derivatives 5. Subsequent treatment with Raney nickel led to alpha-substituted beta,beta-difluoroacrylates 6 in overall yields of 50-80%.