ChemInform Abstract: Difluoromethyl Vinyl Sulfonium Salt: A One-Pot Access to Difluoromethyl-Containing Cyclopropanes

We demonstrate the first preparation of difluoromethyl (CF2H) vinyl sulfonium salt as a new difluoromethylated building block, followed by its application to the synthesis of CF2H-containing cyclopropanes in one step. The salt itself is readily prepared from 3-bromo-3,3-difluoropropene in three steps, in high overall yields, and is stable. A wide range of active methylene compounds participated in the cyclopropanation reaction using this salt, providing the corresponding products in high-to-excellent yields.