Highly Selective Iridium-Catalyzed Asymmetric Hydrogenation of Trifluoromethyl Olefins : A New Route to Trifluoromethyl-Bearing Stereocenters

Fluorine-containing compounds are useful in many applications ranging from pharmaceuticals to ferroelectric crystals. We have developed a new, highly enantioselective synthetic route to trifluoromethyl-bearing stereocenters in up to 96% ee via asymmetric hydrogenation using N,P-ligated iridium catalysts. We also hydrogenated an isomeric mixture of olefins; this reaction gave the hydrogenation product highly enantioselectively (87% ee), and only the E isomer was present after the reaction had reached 56% conversion.