title: Formation of a dihydroborole by catalytic isomerization of a divinylborane.
abstract: Diphenylamino(divinyl)borane (1a) adds two molar equivalents of Piers' borane [HB(C6F5)2] to give the expected double hydroboration product. In contrast diisopropylamino(divinyl)borane (1b) reacts cleanly already with one molar equivalent of HB(C6F5)2 to give the α-borylated tetrahydroborole derivative 10 in good yield. Subsequent treatment of 10 with benzaldehyde proceeded by retro-hydroboration to give the hydroboration product of the aldehyde plus the dihydroborole 3b. We were able to achieve the divinylborane to dihydroborole isomerization (1b to 3b) catalytically: treatment of diisopropylamino(divinyl)borane (1b) with 15 mol% of Piers' borane at elevated temperature gave (diisopropylamino)dihydroborole 3b in good yield.
authors.affiliation: Organisch-Chemisches Institut, Universitat Münster, Corrensstraße 40, 48149 Münster, Germany. erker@uni-muenster.de.
authors.forename: Raúl A
authors.initials: RA
authors.lastname: Adler Yañez
authors.forename: Gerald
authors.initials: G
authors.lastname: Kehr
authors.forename: Constantin G
authors.initials: CG
authors.lastname: Daniliuc
authors.forename: Birgitta
authors.initials: B
authors.lastname: Schirmer
authors.forename: Gerhard
authors.initials: G
authors.lastname: Erker