Flexible N,N,N-chelates as supports for iron and cobalt chloride complexes; synthesis, structures, DFT calculations and ethylene oligomerisation studies

Robust and Electron‐Rich cis‐Palladium(II) Complexes with Phosphine and Carbene Ligands as Catalytic Precursors in Suzuki Coupling Reactions

“…All the NMR spectroscopic signals are also sharp. The successful formation of 10 and 11 was clearly indicated by the downfield shift of the 31 P NMR spectroscopic signals. For example, the 31 P NMR signal shifts from d = 27.6 in 9 to 49.4 ppm in 11.…”

“…The synthetic route for 3 is similar to that for 2. A reaction between 2-(aminomethyl)pyridine and 2-chloroethylamine monohydrochloride under basic conditions afforded N'-(pyridin-2-ylmethyl)ethane-1,2-diamine, [31] which was then treated with triethylorthoformate to produce 2-(4,5-dihydro-1H-imidazol-1-yl)methyl-pyridine. A similar quaternization reaction between the dihydroimidazole and benzyl chloride gave the imidazolinium salt 3 in 72 % yield.…”

Iron-Based and Cobalt-Based Olefin Polymerisation Catalysts

“…While the 2,6-bis(imino)pyridine ligand frame has continued to lead the way, the past 10 years has also seen the development of alternative ligand sets that can act as compatible supports for iron and cobalt ethylene oligomerisation/polymerisation catalysts ( Table 4 ) [46,50,181,182,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,198,199,200,201,202,203,204,205,206,207,208,209] ; active catalysts based on bimetallic iron and cobalt precatalysts have also started to emerge ( Table 5 ) [54,210,211,212,213,214,215] . In the main, these systems show lower activities than the prototype bis(imino)pyridine-based catalysts, although several of these systems have significantly started to approach their catalytic performances (e.g.…”

Synthesis, characterization, and MMA polymerization activity of tetrahedral Co (II) complex bearing N, N-bis(1-pyrazolyl)methyl ligand based on aniline moiety

“…Specifically, the highly active 2,6-bis (imino)pyridines initially discovered independently by the groups of Brookhart and Gibson [7][8][9][10][11] are well known cobalt and iron systems [12][13][14][15][16]. A further modification involves appending a donor side arm to construct tridentate chelating ligands, such as [N,O], [N,N,N], and [N,N,O] ligands [17,18].…”

“…Specifically, the highly active 2,6-bis (imino)pyridines initially discovered independently by the groups of Brookhart and Gibson [7][8][9][10][11] are well known cobalt and iron systems [12][13][14][15][16]. A further modification involves appending a donor side arm to construct tridentate chelating ligands, such as [N,O], [N,N,N], and [N,N,O] ligands [17,18].Moreover, despite many reports on nitrogen-based metal complexes [19,20], little is known about pyrazole-based ligand late transition metal complexes as catalysts for olefin polymerization [21][22][23][24] and methyl methacrylate polymerization, [25][26][27] in comparison with early transition metal complexes [20,[28][29][30][31]. In particular, pyrazoles, which are among the fundamental heterocycles, have been extensively used as N-donor ligands to metals since the first review of pyrazole-derived ligands in 1972 [32][33][34].…”