title: Catalytic Enantioselective Conjugate Alkynylation of α,β-Unsaturated 1,1,1-Trifluoromethyl Ketones with Terminal Alkynes.
abstract: The first catalytic enantioselective conjugate alkynylation of α,β-unsaturated 1,1,1-trifluoromethyl ketones has been carried out. Terminal alkynes and 1,3-diynes were treated with trifluoromethyl ketones in the presence of a low catalytic load of a Cu(I) -MeOBIPHEP complex (2.5 mol %) and triethylamine (10 mol %) to give the corresponding trifluoromethyl ketones bearing a propargylic stereogenic center at the β position with good yields and excellent enantiomeric excesses in most of the cases. No 1,2-addition products were formed under the reaction conditions. The procedure showed broad substrate scope for alkyne, diyne, and enone. A rationale for the observed stereochemistry has been provided. Finally, the potential application of the reaction products in the synthesis of chiral tetrahydrofurans bearing a trifluoromethylated quaternary stereocenter has been devised.
authors.affiliation: Department de Química Orgànica-Facultat de Química, Universitat de València, C/Dr. Moliner 50, 46100, Burjasso, Spain.
authors.forename: Amparo
authors.identifier: http://orcid.org/0000-0002-1729-598X
authors.initials: A
authors.lastname: Sanz-Marco
authors.affiliation: Department de Química Orgànica-Facultat de Química, Universitat de València, C/Dr. Moliner 50, 46100, Burjasso, Spain. gonzalo.blay@uv.es.
authors.forename: Gonzalo
authors.identifier: http://orcid.org/0000-0002-7379-6789
authors.initials: G
authors.lastname: Blay
authors.affiliation: Departament de Física Aplicada, Universitat Politècnica de València, Camí de Vera s/n, 46022, València, Spain.
authors.forename: M Carmen
authors.identifier: http://orcid.org/0000-0003-2630-3897
authors.initials: MC
authors.lastname: Muñoz
authors.affiliation: Department de Química Orgànica-Facultat de Química, Universitat de València, C/Dr. Moliner 50, 46100, Burjasso, Spain. jose.r.pedro@uv.es.
authors.forename: José R
authors.identifier: http://orcid.org/0000-0002-6137-866X
authors.initials: JR
authors.lastname: Pedro
keywords: alkynes; asymmetric catalysis; conjugate addition; enones; fluorine