[3,3]-Sigmatropic Rearrangement/Haller-Bauer Reaction of Aryl Sulfoxides and Selenoxides with Difluoroenoxysilanes: Access to CF2H-Containing Chalcogenides.

A mild and general procedure for the difluoromethylation of organochalcogen compounds has been accomplished via sulfoxide and selenoxide-directed [3,3]-sigmatropic rearrangement/Haller-Bauer reaction with difluoroenoxysilanes. The reactions showed good functional group compatibility, wide substrate applicability, and facile scalability. The synthetic utility is highlighted by the iterative use of this protocol to construct multi-CF2H-containing chalcogenides and the late-stage modification of pharmaceuticals.