title: Radical-polar crossover reactions of vinylboron ate complexes.
abstract: Vinyl boronic esters are valuable substrates for Suzuki-Miyaura cross-coupling reactions. However, boron-substituted alkenes have drawn little attention as radical acceptors, and the radical chemistry of vinylboron ate complexes is underexplored. We show here that carbon radicals add efficiently to vinylboron ate complexes and that their adduct radical anions undergo radical-polar crossover: A 1,2-alkyl/aryl shift from boron to the α-carbon sp2center provides secondary or tertiary alkyl boronic esters. In contrast to the Suzuki-Miyaura coupling, a transition metal is not required, and two carbon-carbon bonds are formed. The valuable boronic ester moiety remains in the product and can be used in follow-up chemistry, enlarging the chemical space of the method. The cascade uses commercial starting materials and provides access to perfluoroalkylated alcohols, γ-lactones, γ-hydroxy alkylnitriles, and compounds bearing quaternary carbon centers.
authors.affiliation: Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstraße 40, 48149 Münster, Germany.
authors.forename: Marvin
authors.identifier: 0000-0002-3012-1319
authors.initials: M
authors.lastname: Kischkewitz
authors.affiliation: Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Kazuhiro
authors.identifier: 0000-0001-8562-3167
authors.initials: K
authors.lastname: Okamoto
authors.affiliation: Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstraße 40, 48149 Münster, Germany.
authors.forename: Christian
authors.identifier: 0000-0002-9742-7400
authors.initials: C
authors.lastname: Mück-Lichtenfeld
authors.affiliation: Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstraße 40, 48149 Münster, Germany. studer@uni-muenster.de.
authors.forename: Armido
authors.identifier: 0000-0002-1706-513X
authors.initials: A
authors.lastname: Studer