Living Polymerization of α-Olefins: Catalyst Precursor Deactivation via the Unexpected Cleavage of a B−C₆F₅ Bond

Abstract

The titanium diamide complex [ArN(CH2)3NAr]TiMe2 (1a; Ar = 2,6-iPr2C6H3) reacts with B(C6F5)3 in pentane to give an insoluble yellow-orange solid (2a). Complex 2a is a catalyst for the living polymerization of 1-hexene. Pentane suspensions of 2a slowly evolve methane over the course of several hours to give the new pentane-soluble derivative [ArN(CH2)3NAr]Ti[CH2B(C6F5)2](C6F5) (3a), which was structurally characterized. Addition of a B−C6F5 group across an intermediate TiCH2 unit is proposed. Compound 3a is inactive for the polymerization of α-olefins.