Pentadienyl migration and abstraction in yttrium aluminabenzene complexes including a single-component catalyst for isoprene polymerization

Aluminabenzene complex [(1-Me-3,5-tBu(2)-C5H3Al)(mu-Me)Y(2,4-dtbp)] (2,4-dtbp = 2,4-di-tert-butylpentadienyl) reacts with LiN(SiHMe2)(2) according to a methyl/silylamido exchange and formation of [(1-Me-3,5-tBu(2)-C5H3Al){mu-N(SiHMe2)(2)}Ln(2,4-dtbp)] which engages in a donor(THF)-dependent reversible Ln-to-Al-pentadienyl migration. The reaction of [(1-Me-3,5-tBu(2)-C5H3Al)(mu-Me)Y(2,4-dtbp)] with [CPh3][B(C6F5)(4)] results in pentadienyl group abstraction affording cationic complex [(1-Me-3,5-tBu(2)-C5H3Al)(mu-Me)Y(benzene)][B(C6F5)(4)] which acts as a single-component catalyst in isoprene polymerization.