[O⁻NS^R]TiCl₃‐Catalyzed Copolymerization of Ethylene with Functionalized Olefins

Abstract

All zipped up: Titanium complexes are designed as efficient catalysts for the copolymerization of ethylene with polar olefins, such as ω‐alkenol and ω‐alkenoic acid. An organophosphine catalyst can be zippered on the polyethylene (see scheme; TBS=tert‐butyldimethylsilyl, FG=functional group, MMAO=modified methylaluminoxane) to form an efficient and recoverable initiator for [3+2] cycloaddition.

Well-defined vanadium complexes as the catalysts for olefin polymerization

“…A remarkable decrease in catalytic activity of 6a-d (at 30 min more than 70% of activity was reduced in contrast with that at 5 min) was observed, whereas catalysts 6e-f, 7 and 8 bearing softer second-row donors (S, P) showed a smaller decrease (ca. 30%), indicating the latter four catalysts possess higher thermal stability [63][64][65][66][67][68]71,72].…”

“…Enhancement of catalytic activity and/or selectivity was observed following the introduction of pendant donor groups in N,O ligands with the group IV metal catalysts; this has been proposed to arise from both steric hindrance and electronic effects [61][62][63][64][65][66][67][68]. The fast deactivation of mono(salicylaldiminato) vanadium(III) complexes took place at high polymerization temperatures, while the thermal stability of the catalysts was enhanced by the introduction of a heteroatom containing group onto the N-aryl moiety of the salicylaldiminato ligands [59,60].…”

Carboranylimine-complexed titanium (IV) organometallics: An investigation of synthesis, structure and catalytic polymerization

“…However, with the co-catalysts trimethylaluminum and tris(pentafluorophenyl)borane, both 4 and 5 demonstrate low activity (<0.01 kg polymer (molTi) À1 h À1 bar À1 ) for ethylene polymerization because of the relatively strong TieCl bonds; (b) under the same conditions, complex 5 is more active than the corresponding analogue 4, which may be caused by the formation of the six-membered ring (Scheme 1) that enhances the intramolecular electron delocalization and reconstruct the molecule configuration differing from 4, the resulting unique bis(cyclo)-coordination model may benefit the olefin polymerization procedure [26]; (c) the obtained polymers have a high molecular weight with reasonable molecular weight distributions (M w /M n are in the range 3.64e4.84) To further elucidate the structure of the obtained ethylene/methyl-10-undecannoate copolymer, products obtained from catalyst 5 have been analyzed by 1 H and 13 C NMR spectra at 110 C in 1,2-dichlorobenzene-d 4 . According to the 1 H NMR spectra, an incorporation ratio of 4.7 mol% methyl-10-undecannoate has been reached in the copolymers; and (d) although the mechanism for the carboranylimine-complexed titanium(IV)/MAO catalytic process is not known in control experiments, neither 2 nor 3 produced polymers in the presence of MAO.…”

Copolymerization of 4-methyl-1-pentene with α,ω-alkenols

“…Polyethylene and polypropylene are the polyolefin resins with the largest commercial scale. It follows then that most researches on the synthesis of the functional polyolefin concern ethylene [4][5][6][7][8][9][10][11][12][13] and propylene [14][15][16][17][18] copolymerization. The investigation on the copolymerization of higher α-olefin with functional monomer was rather rare.…”