title: Photoredox-Catalyzed Stereoselective Conversion of Alkynes into Tetrasubstituted Trifluoromethylated Alkenes.
abstract: A regio- and stereoselective synthesis of trifluoromethylated alkenes bearing four different substituents has been developed. Stereocontrolled sulfonyloxytrifluoromethylation of unsymmetric internal alkynes with an electrophilic CF3 reagent, namely the triflate salt of the Yagupol'skii-Umemoto reagent, in the presence of an Ir photoredox catalyst under visible-light irradiation afforded trifluoromethylalkenyl triflates with well-predictable stereochemistry resulting from anti addition of the trifluoromethyl and triflate groups. Subsequent palladium-catalyzed cross-couplings led to tetrasubstituted trifluoromethylated alkenes in a highly stereoselective manner. The present method is the first example of a facile one-pot synthesis of tetrasubstituted trifluoromethylated alkenes from simple alkynes.
authors.affiliation: Chemical Resources Laboratory, Tokyo Institute of Technology, R1-27, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan).
authors.forename: Ren
authors.initials: R
authors.lastname: Tomita
authors.affiliation: Chemical Resources Laboratory, Tokyo Institute of Technology, R1-27, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan). koike.t.ad@m.titech.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Koike
authors.affiliation: Chemical Resources Laboratory, Tokyo Institute of Technology, R1-27, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan). makita@res.titech.ac.jp.
authors.forename: Munetaka
authors.initials: M
authors.lastname: Akita
mesh_terms: D000475:Alkenes / Q000138:chemical synthesis* / Q000737:chemistry; D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D006845:Hydrocarbons, Fluorinated / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010084:Oxidation-Reduction; D055668:Photochemical Processes; D013237:Stereoisomerism
chemical_list: D000475:Alkenes; D000480:Alkynes; D006845:Hydrocarbons, Fluorinated
keywords: alkenes; alkynes; fluorine; photocatalysis; trifluoromethylation