Copper-Mediated Difluoromethylation of Aryl and Vinyl Iodides

Selectively fluorinated molecules are important as materials, pharmaceuticals, and agrochemicals, but their synthesis by simple, mild, laboratory methods is challenging. We report a straightforward method for the cross-coupling of aryl and vinyl iodides with a difluormethyl group generated from readily available reagents to form difluoromethylarenes and difluoromethyl-substituted alkenes. The reaction of electron-neutral, electron-rich, and sterically hindered aryl and vinyl iodides with the combination of CuI, CsF and TMSCF2H leads to the formation of difluoromethyl-substituted products in high yield with good functional group compatibility. This transformation is surprising, in part, because of the prior observation of the instability of CuCF2H.