Preparation and addition-elimination reactions of benzyl α,β,β-trifluoroacrylate. A new stereoselective approach to (Z)-β-substituted α,β-difluoroacrylates

Article abstract of DOI:10.1021/jo701975y

(Chemical Equation Presented) Benzyl α,β,β- trifluoroacrylate (1) was prepared in good yield via the reductive Br-F elimination of benzyl 2-bromo-2,3,3,3-tetrafluoropropanoate or the palladium-catalyzed cross-coupling reaction of 1,2,2-trifluorovinylstannane with benzyl chloroformate. On treating 1 with various Grignard reagents or dialkylzinc reagents in the presence of copper(I) salt, the corresponding β-substituted α,β-difluoroacrylates were obtained in high yields with high Z-selectivity. Additionally, trialkylaluminum reagents were also found to be good nucleophiles, the corresponding addition-elimination products being afforded in good yields but with low stereoselectivity.