Copper-Catalyzed Trifluoromethylation of Vinylsiloxanes

Trifluoromethylated alkenes are shown to be readily synthesized from the corresponding vinylsiloxanes using a simple copper-catalyzed trifluoromethylation with Umemoto’s reagent II. Upon simple activation with tetrabutylammonium triphenyldifluorosili-cate in the presence of Kubas’ salt and without an additional exogenous ligand, they were indeed found to be easily trifluoro-methylated with high levels of stereospecificity. In addition to a broad substrate scope and mild reaction conditions, this route to trifluoromethylated alkenes enables the synthesis of all E, Z and branched isomers.