The Search for New-Generation Olefin Polymerization Catalysts: Life beyond Metallocenes

Abstract

Even late transition metal complexes function as active and selective catalysts for α-olefin polymerization. The discovery of a highly active family of catalysts 1 based on iron, a metal that had no previous track record in this field, has highlighted the possibilities for further new catalyst discoveries. As a result, an intense search has developed for new-generation catalysts, in both academic and industrial research laboratories. R =H, Me; R =Me, iPr; R =H, Me, iPr; R =H, Me; X=halide.

Z. Guan, Control of polymer topology through late‐transition‐metal catalysis, J Polym Sci Part A: Polym Chem (2003), 41(22), 3680–3692

“…90 Although early-transition-metal catalysts such as Ziegler-Natta catalysts and early-transitionmetal metallocene catalysts remain the workhorses of the polyolefin industry, significant advances have been made recently in late-transition-metal polymerization catalysts. [43][44][45][46][47][48][49] Two attributes of late-transition-metal polymerization catalysts distinguish them from early-transitionScheme 9. Synthesis of cyclic PE with ROMP.…”

“…50 -57,83-88 We are currently focusing on the development of new catalysts, the synthesis of new functional materials, and the design of polymers with unconventional topologies by using late-transitionmetal catalysts. Given the unique features of latetransition-metal polymerization catalysts and the recent rapid development of new catalyst designs, [43][44][45][46][47][48][49] the future of designing new polymeric materials with late-transition-metal catalysts is very promising.…”

“…Inspired by the recent progress in late-transition-metal polymerization catalysis, [43][44][45][46][47][48][49] we have been exploring the concept of controlling polymer topology with late-transition-metal catalysts with the goal of creating polymers with new topologies from simple existing monomers (Fig. 2).…”

Living polymerization of olefins with ansa-dimethylsilylene(fluorenyl)(amido)dimethyltitanium-based catalysts

“…As chain transfer via b-elimination and/or transmetalation with trialkylaluminum as a cocatalyst is inevitable in conventional Ziegler-Natta catalytic systems; homogeneous V(acac) 3 /Et 2 AlCl (where acac is acetylacetonate or its analog) had previously been the only catalytic system that produced syndiotactic-rich living polypropylene (PP) at À78 1C. 1,2 The development of metallocene catalysts has enabled us to produce a variety of uniform olefin copolymers and to control the stereoregularity of poly(1-alkene)s. 3,4 The success of metallocene catalysts has stimulated research on transition metal complexes for olefin polymerization, [5][6][7] so-called single-site catalysts, which has also resulted in various transition metal complexes for the living polymerization of olefins. 8,9 We have also developed a living polymerization system using ansa-dimethysilylene(fluorenyl)(amido)dimethyltitanium, Me 2 Si(Z 3 -C 13 H 8 )(Z 1 -N t Bu)TiMe 2 (1), combined with a suitable cocatalyst.…”

Ti (IV) Complexes of Some Heterocyclic Ligands Synthesis, Characterization and Ethylene Polymerization Activity

“…In polyolefin chemistry, an increasing interest has been focused on the exploration and development of homogeneous transition metal catalysts, as a result of an increasing demand for polyethylene [25][26][27][28][29][30] . The vanadium complexes of bis(benzimidazole)amine tridentate ligands [N, N, N], were reported as active ethylene polymerization catalysts after activation with simple alkylaluminum compounds 31 2,6-Bis(2-benzimidazolyl)pyridine zirconium dichloride / MAO polymerizes methylacrylate 32 Recently, [33][34][35][36][37][38][39] we reported the ethylene polymerization activity of benzimidazole, benzothiazole, benzoxazole and 2-(benzimidazolyl) pyridine titanium zirconium and vanadium complexes.…”