title: Lewis acid catalysis: catalytic hydroboration of alkynes initiated by Piers' borane.
abstract: Terminal and internal alkynes are efficiently hydroborated to (E)-alkenyl pinacol boronic esters with excellent yields and selectivities using a Lewis acid catalyst. In the case of Piers' borane (HB(C6F5)2) the borane acts as a pre-catalyst generating dissymmetrically gem-diborylated species of the form RCH2CR'(Bpin)(B(C6F5)2) which are the active catalysts.
authors.affiliation: Department of Chemistry, University of Toronto, 80 St. George St., Toronto, Ontario M5S 3H6, Canada. dstephan@chem.utoronto.ca.
authors.forename: Mirco
authors.initials: M
authors.lastname: Fleige
authors.forename: Juri
authors.initials: J
authors.lastname: Möbus
authors.forename: Thorsten
authors.initials: T
authors.lastname: Vom Stein
authors.forename: Frank
authors.initials: F
authors.lastname: Glorius
authors.forename: Douglas W
authors.initials: DW
authors.lastname: Stephan