Synthesis of Trifluoromethylated Alkenes: Hypervalent Iodine Meets High-Valent Copper.

The first trifluoromethylation of vinylbenziodoxolones (VBX) is reported herein. The synthetic method is based on the use of bench-stable, high-valent copper(III) species, and the reaction can be initiated under thermal conditions and/or irradiation (365 nm) giving access to trifluoromethylated alkenes in a stereoselective fashion. Various VBX reagents derived from tyrosine, cysteine, small peptides, thiols and amides can be used as precursors. The obtained alkenes could be further functionalized by reduction or epoxidation of the trifluoromethylated double bond. Furthermore, the method could be applied in a large-scale batch/flow synthesis and could be conducted under visible light irradiation.