Pyrazolyl-pyrimidine based ligands in palladium catalyzed copolymerization and terpolymerization of CO/olefins

Alternating and Non‐Alternating Pd‐Catalysed Co‐ and Terpolymerisation of Carbon Monoxide and Alkenes

“…[49] In the case of pyrimidine-pyrazole ligands, the coordination to the palladium centre to give [PdMe(NCMe)-(N-NЈ)] + complexes was found to be directed by the steric bulk of the pyrazole moiety. [49,50] Indeed, when ligand 18 was used, the pyrazole moiety was found to be in a cis position to the PdMe group. However, when methyl substituents were introduced in positions 3 and 5 of the pyrazole unit (ligand 19), the pyrimidine moiety was found to be cis to the methyl group.…”

“…[51] This effect is shown in Figure 10 The cationic palladium systems [PdMe(NCMe)(N-NЈ)]-[BArF] containing imidazolyl-pyridine ligands cis-12, cis-13, cis-and trans-15 and pyrazolyl-pyridines 18, 20 and 21 have also been used for the terpolymerisation of CO/TBS/ ethene. [50,52] It was found that the choice of the olefin preferentially inserted into the terpolymer is strictly related to the nature of the nitrogen ligand present in the catalyst and not only to the kind of ligand. Thus, a slight modification in the chelating N ligands coordinated to palladium terpolymerisation catalysts leads to unexpected results in the composition of the terpolymers.…”

(Iminopyridine)Pd (II) complexes as versatile catalysts for copolymerization and terpolymerization of vinyl arene, ethylene, and carbon monoxide

“…N‐N ligands exhibit greater catalytic activities than P‐P ligands for the copolymerization of vinyl arene and CO. [ 9–17 ] Moreover, N‐N ligands such as bipyridine, phenanthroline, and pyridine‐imidazoline are also employed for the terpolymerization of CO, vinyl arene, and ethylene (Figure 1). [ 18–20 ] While a variety of ligand‐modified palladium catalysts are used to polymerize various olefins and CO, direct comparisons of the catalytic activities among catalyst systems for the copolymerization and terpolymerization of ethylene, vinyl arenes, and CO has not yet been reported.…”

Zinc(II) and cadmium(II) complexes based on 2-(3,5-dimethyl-1H-pyrazol-1-yl)-6-(4-methoxyphenyl)pyrimidine-4-carboxylic acid: Synthesis, structure and luminescence

“…Among various pyrazolylpyrimidines, 2-(pyrazolyl)pyrimidines have attracted most attention as the ligands for the synthesis of transition metal complexes [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. These complexes are of fundamental and practical importance since they manifest various kinds of biological and catalytic activity [8,14,19].…”

“…These complexes are of fundamental and practical importance since they manifest various kinds of biological and catalytic activity [8,14,19]. Other pyrimidine-based compounds, pyrimidine-4(6)-carboxylic acids and corresponding carboxylates also were reported as the ligands [20][21][22][23].…”