KSO-Mediated Selective Trifluoromethylacylation and Trifluoromethylarylation of Alkenes under Transition-Metal-Free Conditions: Synthetic Scope and Mechanistic Studies.

A practical and efficient method for selective intramolecular radical trifluoromethylacylation and -arylation of alkenes with inexpensive CFSONa and KSO in aqueous media has been developed, respectively, affording the highly chemoselective synthesis of CF-functionalized chroman-4-ones and chromanes in satisfactory yields. Control experiments and DFT calculations indicate that the CFSONa/KSO system is capable of trifluoromethylating the substrate of alkenes without a transition metal catalyst and the oxidation of CFSONa to ·CF by KSO is involved in the rate-determining step.