78009-23-1Relevant articles and documents
O -aryloxide-N-heterocyclic carbenes: Efficient synthesis of the proligands and their p -cymene ruthenium complexes
Yang, Dandan,Tang, Yungang,Song, Haibin,Wang, Baiquan
, p. 2012 - 2017 (2015)
An efficient method to synthesize o-hydroxyaryl-substituted imidazoles (2-OH-3-R-5-tBuC6H2)(C3H3N2) [R = tBu (1a), H (1b)] was developed through copper-catalyzed C-N bond formation. Treatment of 1a or 1b with a halohydrocarbon in refluxing toluene afforded a series of o-hydroxyaryl imidazolinium proligands 2a-h in high yields. Reactions of proligands 2a-h with Ag2O and [(p-cymene)RuCl2]2 gave the corresponding o-aryloxide-N-heterocyclic carbene ligated p-cymene ruthenium complexes 3a-h. All the imidazolium salts and ruthenium complexes were fully characterized by 1H and 13C NMR spectra, elemental analysis, and high-resolution mass spectrometry. Without the cocatalyst or irradiation, these complexes can efficiently catalyze norbornene ring-opening metathesis polymerization. Notably, the structures of the catalysts were found to have significant effects on the catalytic activity and the properties of obtained polymers.
