Trifluoromethylation of Allylsilanes under Copper Catalysis

Branched allylic CF3 products are accessible by copper-catalyzed trifluoromethylation of allylsilanes with the Togni reagent I. The silyl group is critical to control the outcome of this reaction because in its absence, a product of addition between the alkene and the Togni reagent is formed preferentially. The reaction is inhibited with 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) and is likely to operate via multiple reaction pathways.