Pyridine-amido aluminum catalyst precursors for 1,3-butadiene transition-metal-free stereospecific polymerization

Abstract

Aluminum-based transition-metal-free catalysts for α-olefin polymerization have garnered extensive research interest from academia and industries over the past two decades. However, it has been a long-standing challenge to achieve the...

Iminopyridine Copper Complex‐Based Catalysts for 1,3‐Dienes Stereospecific Polymerization

“…Finally, a further hypothesis of mechanism, as suggested by one of the referees, and on the basis of what reported in the literature by Hua et al., [ 46 ] foresees that the copper complexes with iminopyridine ligand, on activation with MAO, lead to pyridyl‐amido AlMe 2 complexes with dissociation of copper salt, and the pyridyl‐amido AlMe 2 complexes actually act as the real active species of the polymerization. Accepting the referee's suggestion, we investigated the polymerization of butadiene and isoprene, under the polymerization conditions described in the present paper, using only methylaluminoxane in combination with the pyridylimine ligand.…”

“…Nevertheless, the presence of a sort of equilibrium through which the ligand may transfer from the metal atom to MAO or migrate from one metal atom to another one appears quite plausible, since it has already been postulated in the case of polymerization of 1,3-butadiene with some cobalt-based catalytic systems. [45] Finally, a further hypothesis of mechanism, as suggested by one of the referees, and on the basis of what reported in the literature by Hua et al, [46] foresees that the copper complexes with iminopyridine ligand, on activation with MAO, lead to pyridylamido AlMe 2 complexes with dissociation of copper salt, and the pyridyl-amido AlMe 2 complexes actually act as the real active species of the polymerization. Accepting the referee's suggestion, we investigated the polymerization of butadiene and isoprene, under the polymerization conditions described in the present paper, using only methylaluminoxane in combination with the pyridylimine ligand.…”

Ultrahigh activity and broad temperature resistance of amine–imine cobalt precatalysts for butadiene polymerization

“…60 Synthesis of ligands α-diimine was prepared according to literature procedures in high yield. 43,61 ArNvC(Me)-C(Me)( n Bu)-NHAr (Ar = 2,6-diisopropylphenyl) (L1). The typical procedure was basically according to the literature procedures.…”

Aluminum complexes of a hemilabile pyrrolylaldiminate ligand

“…Aluminum complexes containing formally anionic N-donor ligands have received considerable attention because of their essential roles in Lewis acid catalysis [1][2][3][4][5] and polymerization chemistry [6][7][8][9][10]. Chelating ligands investigated in this regard (Figure 1a) include bidentate [N^N] À [11][12][13][14][15][16][17][18][19][20][21], [N^O] À [21][22][23][24], [N^S] À [25],…”

“…Aluminum complexes containing formally anionic N‐donor ligands have received considerable attention because of their essential roles in Lewis acid catalysis [1–5] and polymerization chemistry [6–10]. Chelating ligands investigated in this regard (Figure 1a) include bidentate [N^N] − [11–21], [N^O] − [21–24], [N^S] − [25], [N^P] − [26, 27], tridentate [P^N^N] − [28], [P^N^P] − [29], [N^E^N] 2− (E = O, NR) [4], and tetradentate triamidoamine [30], salen [31], salan [32], porphyrin [33], calix[4]pyrrole [34], etc. We have previously reported aluminum chemistry employing [PyIm] − [16], [R‐NP] − (R = Me, i Pr) [27], [PNN] − [28], and [R‐PNP] − (R = Ph, i Pr) [29] ligands (Figure 1b).…”