Minnick, Jennifer L. published the artcileC-X (X = N, O) cross-coupling reactions catalyzed by copper-pincer bis(N-heterocyclic carbene) complexes, Safety of 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride, the publication is Frontiers in Chemistry (Lausanne, Switzerland) (2019), 12pp., database is CAplus and MEDLINE.
The application of these complexes in Ullmann-type C-X (X = N, O) coupling of azoles such as 1H-imidazole, benzimidazole, pyrazole and phenols such as phenol, p-cresol with aryl halides ArI (Ar = Ph, 1-phenylethan-1-one, 2-methylphenyl, etc.) in a relatively short reaction time has been reported. In contrast to other well-defined copper(I) catalysts that require an inert atm. for an efficient C-X coupling, the employed Cu(I)-pincer bis(NHC) complexes provide good to excellent yields in air. The air-assisted reactivity, unlike that in the Sonogashira reaction, is also affected by the base employed and the reaction time. With Cs2CO3 and K2CO3, the oxygen-generated catalyst is more reactive than the catalyst formed under argon in a short reaction time (12 h). However, the difference in reactivity is compromised after a 24 h reaction with K2CO3. The efficient pincer Cu-NHC/O2/Cs2CO3system provides great to excellent cross-coupling yields for electronically diverse aryl iodides and imidazole derivatives The catalyst scope is controlled by a balance between nucleophilicity, coordinating ability, and steric hindrance of aryl halides and N-/O-nucleophiles.
Frontiers in Chemistry (Lausanne, Switzerland) published new progress about 258278-25-0. 258278-25-0 belongs to imidazoles-derivatives, auxiliary class Achiral NHCs Ligands, name is 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride, and the molecular formula is C27H39ClN2, Safety of 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride.
Referemce:
https://en.wikipedia.org/wiki/Imidazole,
Imidazole | C3H4N2 – PubChem