摘要:
Three series of alpha-halo-alpha,alpha-difluoromethyl ketones are prepared from highly alpha-fluorinated gem-dials by exploiting the facile release of trifluoroacetate, followed by immediate trapping of the liberated alpha,alpha-difluoroenolate with an electrophilic chlorine, bromine, or iodine source. The products are typically isolated in good yields, even in the case of sensitive, alpha-iodo-alpha,alpha-difluoromethyl ketones. Also, we demonstrate that an alpha-iodo-alpha,alpha-difluoromethyl ketone will participate in a copper-promoted reaction to forge a new carbon-carbon bond.