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

Abstract

Aluminabenzene complex [(1-Me-3,5-tBu₂-C₅H₃Al)(μ-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-tBu₂-C₅H₃Al){μ-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-tBu₂-C₅H₃Al)(μ-Me)Y(2,4-dtbp)] with [CPh₃][B(C₆F₅)₄] results in pentadienyl group abstraction affording cationic complex [(1-Me-3,5-tBu₂-C₅H₃Al)(μ-Me)Y(benzene)][B(C₆F₅)₄] which acts as a single-component catalyst in isoprene polymerization.