title: Organocatalytic Enantioselective Vinylogous Pinacol Rearrangement Enabled by Chiral Ion Pairing.
abstract: An enantioselective pinacol rearrangement of functionalized (E)-2-butene-1,4-diols was developed. In the presence of a catalytic amount of a chiral BINOL-derived N-triflyl phosphoramide, these 1,4-diols rearranged to β,γ-unsaturated ketones in excellent yields and enantioselectivities. The formation of a chiral ion pair between the intermediary allylic cation and the chiral phosphoramide anion was postulated to be responsible for the highly efficient chirality transfer. These chiral building blocks were further converted into enantioenriched polysubstituted tetrahydrofuran and tetrahydronaphthalene derivatives.
authors.affiliation: Laboratory of Synthesis and Natural Products, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, BCH 5304, 1015, Lausanne, Switzerland.
authors.forename: Hua
authors.initials: H
authors.lastname: Wu
authors.affiliation: Laboratory of Synthesis and Natural Products, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, BCH 5304, 1015, Lausanne, Switzerland.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Laboratory of Synthesis and Natural Products, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, BCH 5304, 1015, Lausanne, Switzerland.
authors.forename: Jieping
authors.initials: J
authors.lastname: Zhu
keywords: 1,4-diols; chiral Brønsted acids; ion pairs; organocatalysis; pinacol rearrangements