61698-31-5Relevant academic research and scientific papers
Effect of ortho-substituents on the stereochemistry of 2-(o-substituted phenyl)-1H-imidazoline-palladium complexes
Gan, Zhibin,Kawamura, Kenjiro,Eda, Kazuo,Hayashi, Masahiko
experimental part, p. 2022 - 2029 (2010/09/20)
Palladium complexes composed of [Pd(Ln)2Cl2] (n = 1, 2, 3, 4, 6), [L5a]2[PdCl4] and [Pd(L5b)2], where L1 = 4,5-dihydro-2-phenyl-1H-imidazole (=2-phenyl-1H-imidazoline), L2 = 2-(o-fluorophenyl)-1H-imidazoline, L3 = 2-(o-methylphenyl)-1H-imidazoline, L4 = 2-(o-tert-butylphenyl)-1H-imidazoline, L5a = 2-(o-hydroxyphenyl)-1H- imidazolinium, L5b = 2-(1H-imidazolin-2-yl)phenolate, and L6 = 2-(o-methylphenyl)-1H-imidazole, were synthesized. Molecular structures of the isolated palladium complexes were characterized by single crystal X-ray diffraction analysis. The effect of ortho-substituents on the phenyl ring on trans-chlorine geometry was noted for complexes [Pd(L1)2Cl 2] 1a and 1b, [Pd(L2)2Cl2] 2 and [Pd(L6) 2Cl2] 6, whereas cis-chlorine geometry was observed for [Pd(L3)2Cl2] 3 and [Pd(L4)2Cl2] 4. PdCl2 reacts with 2-(o-hydroxyphenyl)-1H-imidazoline in DMF to give [L5a]+ and [L5b]- so that [L5a]2[PdCl 4] 5a and [Pd(L5b)2] 5b were obtained. In complex 5b, as an N,O-bidentate ligand, two ligands L5b coordinated with the central Pd(II) ion in the trans-form. The coordination of PdCl2 with 2-(o-hydroxyphenyl)-1H-imidazolines in solution was investigated by NMR spectroscopy. Palladium complexes composed of [Pd(Ln)2Cl2] (n = 1, 2, 3, 4, 6), [L5a]2[PdCl4] and [Pd(L5b)2], where L1 = 4,5-dihydro-2-phenyl-1H-imidazole (= 2-phenyl-1H-imidazoline), L2 = 2-(o-fluorophenyl)-1H-imidazoline, L3 = 2-(o-methylphenyl)-1H-imidazoline, L4 = 2-(o-tert-butylphenyl)-1H-imidazoline, L5a = 2-(o-hydroxyphenyl)-1H-imidazolinium, L5b = 2-(1H-imidazolin-2-yl) phenolate, and L6 = 2-(o-methylphenyl)-1H-imidazole, were synthesized and characterized by single crystal X-ray diffractometry.
Efficient and highly regioselective direct C-2 arylation of azoles, including free (NH)-imidazole, -benzimidazole and -indole, with aryl halides
Bellina, Fabio,Calandri, Chiara,Cauteruccio, Silvia,Rossi, Renzo
, p. 1970 - 1980 (2007/10/03)
The Pd- and Cu-mediated reaction of a large variety of π-electron sufficient heteroarenes, which include free (NH)-imidazoles, -benzimidazole and -indole, with aryl iodides under ligandless and base-free conditions provides regioselectively the required 2-arylheterocycle derivatives in high yields. 2-Aryl-1-phenyl-1H-imidazoles can also be prepared by a one-pot domino HALEX and Pd- and Cu-mediated arylation reactions of 1-phenyl-1H-imidazole with activated and unactivated aryl bromides under base-free and ligandless conditions. The protocol for the synthesis of 2-arylazoles involving the use of aryl iodides has been found to be suitable for the efficient preparation of three bioactive compounds and a key intermediate in the synthesis of a heparanase inhibitor.
Palladium- and copper-mediated direct C-2 arylation of azoles - Including free (NH)-imidazole, -benzimidazole and -indole - Under base-free and ligandless conditions
Bellina, Fabio,Cauteruccio, Silvia,Rossi, Renzo
, p. 1379 - 1382 (2007/10/03)
The first palladium- and copper-mediated C-2 arylations of thiazole, oxazole, N-methylimidazole and N-arylimidazoles, as well as of free (NH)-imidazole, -benzimidazole and -indole, with aryl iodides under ligandless and base-free conditions are described. Complete selectivity has been achieved under these unprecedented conditions, which allow the use of substrates containing base-sensitive groups, such the NH groups of imidazole, benzimidazole or indole, without their prior protection. No N-arylation products were detected in the arylation of free (NH)-imidazole, -benzimidazole and -indole. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
New one-step synthesis of 2-aryl-1H-imidazoles: Dehydrogenation of 2-aryl-δ2-imidazolines with dimethylsulfoxide
Anastassiadou,Baziard-Mouysset,Payard
, p. 1814 - 1816 (2007/10/03)
A new one-step method for the preparation of 2-aryl-1Himidazoles 3, based on the DMSO dehydrogenation of 2-aryl-Δ2-imidazolines, is described. A comparative study between DMSO and 10% Pd/C, the best known catalyst employed in this transformation, has also been developed. Both protocols were carried out at 120 °C for 48 hours.
2,5-DIAZACYCLOPENTADIENYLIDENE: A STANDARD CARBENE OR A HIGHLY REACTIVE DIRADICAL?
Bru, Nuria,Vilarrasa, Jaume
, p. 1489 - 1492 (2007/10/02)
2,5-Diazacyclopentadienylidene (2H-imidazolidene), generated either by photolysis or thermolysis from 2-diazo-2H-imidazole, reacts with benzene derivatives to give mainly a mixture of o-, m-, p-substitued 2-phenylimidazoles.The carbene shows a strong diradical character, in sharp contrast with the well-known behavior of cyclopentadienylidene.
