Fluoro-Wacker Gem -Difluorination of Alkene via Fluoropalladation and Dyotropic Rearrangement

Nucleopalladation of alkenes is a fundamental elementary step in palladium catalysis and underpins a wide range of alkene functionalization reactions. However, fluoropalladation using readily accessible and synthetically practical fluoride sources remains markedly underdeveloped. We report herein a palladium-catalyzed migrative 1,1-difluorination of 1,1-disubstituted alkenes that proceeds through nucleophilic fluoropalladation, oxidation of the resulting alkyl-Pd(II) intermediate to Pd(IV), and a subsequent 1,2-C sp 3 /Pd(IV) dyotropic rearrangement. The triethylamine tris(hydrogen fluoride) complex (Et 3 N·3HF) serves as an efficient nucleophilic fluoride source and is fully compatible with Selectfluor, which oxidizes Pd(II) to Pd(IV) and triggers migratory rearrangement. This work establishes fluoropalladation-initiated Pd(IV) dyotropic rearrangement as a viable mechanistic platform for migrative alkene difunctionalization and enables efficient conversion of 1,1-disubstituted alkenes into ring-expanded or chain-extended products bearing a gem -difluoromethylene unit.