Three-Component Friedel-Crafts Transformations: Synthesis of Alkyl and Alkenyl Trifluoromethyl Sulfides and Alkenyl Iodides.

Straightforward and mild hexafluoroisopropanol (HFIP)-mediated, metal-free, three-component Friedel-Crafts approaches are reported for the synthesis of alkenyl and alkyl trifluoromethyl sulfides from arenes, (PhSO2)2NSCF3, and alkynes or alkenes, respectively. The transformations proceed with high regio- and stereochemical control via the initial formation of cationic thiirenium and thiiranium intermediates, respectively, followed by Friedel-Crafts reactions with the arene. A mechanistically related three-component synthesis of alkenyl iodides from arenes, alkenes, and N-iodosuccinimide is also reported.