1040403-31-3Relevant articles and documents
2-Phenylimidazole-PdCl2 and 2-phenylimidazoline-PdCl2 complexes: Single-crystal and powder X-ray diffractometry,1H NMR spectra, and comparison of catalytic activities in coupling reactions
Kawamura, Kenjiro,Haneda, Satoshi,Gan, Zhibin,Eda, Kazuo,Hayashi, Masahiko
, p. 3748 - 3752 (2008)
Single-crystal X-ray diffractometry and powder X-ray diffractometry of the complexes dichlorobis(2-phenyl-1H-imidazole)palladium(II) (1) and dichlorobis(2-phenyl-4,5-dihydro-1H-imidazole)palladium(II) (2) and 1H NMR structure elucidation in DMF-d7 solution are discussed. In the case of complex 1, we found that changing the solvent for recrystallization from a mixture of DMF and toluene (method A) to only DMF (method B) afforded complexes 2 and 2′, having crystallographically different structures. 1H NMR studies indicated that the spectra of the solid samples 2 and 2′ are the same in DMF-d7. This indicated that the Pd-N bond rotates easily in solution, whereas complexes 2 and 2′ coexist through strong packing in the solid state. The catalytic activities of Pd complexes 1 and 2 in coupling reactions such as the Mizoroki-Heck reaction and Suzuki-Miyaura coupling will also be disclosed.
Structure, dynamics and catalytic activity of palladium(II) complexes with imidazole ligands
Szulmanowicz,Zawartka,Gniewek,Trzeciak
, p. 4346 - 4354 (2011/03/17)
Several palladium complexes of the type [Pd(im)2Cl2], [Pd(im)3Cl]Cl, and [Pd(im)4]Cl2 (im = imidazole 1, 1-methylimidazole 2, 1,2-dimethylimidazole 3, 1-butylimidazole 4, 4a, 1-phenylimidazole 6, 1-phenylimidazoline 7, and 1-methylimidazoline 8) were prepared and structurally characterized. The square planar structure of two new complexes with the composition [Pd(im)4]Cl2 (2b, 4b) was confirmed by X-ray analysis. In solution, exchange of imidazole ligands leading to heteroleptic products was evidenced by ESI-MS studies. Two bis-ligated complexes, bearing 1-methylimidazole (2a) and 1-propoxymethylimidazole (5) ligands, were obtained in the reaction of palladium with imidazoles formed by deprotection of one nitrogen atom in the respective imidazolium halides. Catalytic Suzuki-Miyaura reactions were carried out using the obtained palladium complexes in isopropanol-water solution. High yields of the cross-coupling products were obtained at 40 and 60 °C when 2-bromotoluene, 4-bromotoluene, and 4-bromoanizole were used as substrates.
