The author of 《N-Heterocyclic Olefin-Ligated Palladium(II) Complexes as Pre-Catalysts for Buchwald-Hartwig Aminations》 were Watson, Ian C.; Schumann, Andre; Yu, Haoyang; Davy, Emma C.; McDonald, Robert; Ferguson, Michael J.; Hering-Junghans, Christian; Rivard, Eric. And the article was published in Chemistry – A European Journal in 2019. Reference of 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride The author mentioned the following in the article:
New N-heterocyclic olefins (NHOs) are described with functionalization on the ligand heterocyclic backbone and terminal alkylidene positions. Various PdII-NHO complexes I (Ar = 2,6-iPr2C6H3; L = 3-chloropyridine; R = Me, RR =9,10-acenaphthylenediyl) and were prepared by cleavage of chloro-bridged dimers (I-L)2 with pyridine ligand; the complexes were evaluated as pre-catalysts in Buchwald-Hartwig aminations. Vinylogous complex [(Me2Dipp2Im-2-CH:CHCH2Pd)Cl2L] (13) was prepared by palladation of 1,3-Dipp2-4,5-dimethyl-2-(2-propenylidene)imidazoline. The most active system for catalytic C-N bond formation between hindered arylamine and haloarene substrates was accessed by combining a backbone methylated NHO with [Pd(cinnamyl)Cl]2 in the presence of NaOtBu as a base. In these active systems evidence suggests that catalysis is mediated by colloidal palladium metal, highlighting a different coordination ability of NHOs in comparison with commonly used N-heterocyclic carbene co-ligands.1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride(cas: 258278-25-0Reference of 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride) was used in this study.
1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride(cas: 258278-25-0) has been employed in an efficient, one-pot synthesis of N-heterocyclic carbene-allylpalladium complexes.Reference of 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chlorideIn addition, it can efficiently catalyze the Suzuki-Miyaura coupling of aryl chlorides with aryl boronic acids.
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem