title: Palladium-Catalyzed Oxidative Carbocyclization-Borylation of Enallenes to Cyclobutenes.
abstract: A highly efficient palladium-catalyzed oxidative borylation of enallenes was developed for the selective formation of cyclobutene derivatives and fully-substituted alkenylboron compounds. Cyclobutenes are formed as the exclusive products in MeOH in the presence of H2 O and Et3 N, whereas the use of AcOH leads to alkenylboron compounds. Both reactions showed a broad substrate scope and good tolerance for various functional groups, including carboxylic acid ester, free hydroxy, imide, and alkyl groups. Furthermore, transformations of the borylated products were conducted to show their potential applications.
authors.affiliation: Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 10691, Stockholm, Sweden.
authors.forename: Youai
authors.initials: Y
authors.lastname: Qiu
authors.affiliation: Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 10691, Stockholm, Sweden.
authors.forename: Bin
authors.initials: B
authors.lastname: Yang
authors.affiliation: Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 10691, Stockholm, Sweden. Zhu.Can@su.se.
authors.forename: Can
authors.initials: C
authors.lastname: Zhu
authors.affiliation: Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 10691, Stockholm, Sweden. jeb@organ.su.se.
authors.forename: Jan-E
authors.initials: JE
authors.lastname: Bäckvall
keywords: allenes; borylation; cyclobutenes; oxidation; palladium