Diverse reactivity of the gem-difluorovinyl iodonium salt for direct incorporation of the difluoroethylene group into N- and O-nucleophiles.

The synthesis of gem-difluoroethylene compounds remains a difficult task in organic synthesis. Here, the direct difluoroethylation reactions of N- and O-nucleophiles including amides and acids were realized with a hypervalent iodine reagent: gem-difluorovinyl iodonium salt (DFVI). The reactions were accomplished via a neighbouring group rearrangement.

Synthesis of Naphthalenyl Triflates via the Cationic Annulation of Benzodiynes with Triflic Acid.

A highly efficient and regioselective annulation of benzodiynes promoted by triflic acid has been developed. This protocol provides a step and atom-economic access to a series of naphthalenyl triflates. Furthermore, direct synthetic applications of this reaction are also elaborated through cross-coupling reactions to generate synthetically useful multisubstituted naphthalenes.