Herein we present a novel strategy based on palladium-catalyzed allylic alkylation by taking advantage of the nucleophilic addition of external fluoride onto gem-difluoroalkenes as the initiation step. The merit of this protocol is highly appealing, as it enables a formal allylation of trifluoroethylarene derivatives through the in situ generation of β-trifluorocarbanions, which otherwise are deemed to
Tetrahydrofuran, 1,3-dioxolane, hexanal, and benzaldehyde react readily with beta,beta-difluoroacrylates under free radical conditions to furnish adducts in moderate to high yield.
Synthesis of β,β-difluoroacrylates
作者:Carl L. Bumgardner、Jason P. Burgess、T.Stephen Everett、Suzanne T. Purrington
DOI:10.1016/s0022-1139(00)81101-x
日期:1992.2
Diethyl malonates substituted in the alpha-position by an alkyl group may be bromodifluoromethylated to give derivatives suitable for conversion to beta,beta-difluoro-alpha-alkylacrylates. The final step involves dealkoxycarbonylation-elimination promoted by potassium bromide in dimethyl sulfoxide.