In 2014,Chemistry – A European Journal included an article by Morozov, Oleg S.; Lunchev, Andrey V.; Bush, Alexander A.; Tukov, Aleksandr A.; Asachenko, Andrey F.; Khrustalev, Victor N.; Zalesskiy, Sergey S.; Ananikov, Valentine P.; Nechaev, Mikhail S.. Product Details of 852445-84-2. The article was titled 《Expanded-Ring N-Heterocyclic Carbenes Efficiently Stabilize Gold(I) Cations, Leading to High Activity in π-Acid-Catalyzed Cyclizations》. The information in the text is summarized as follows:
Six- and seven-membered expanded-ring N-heterocyclic carbene (er-NHC) Au(I) complexes were synthesized using different synthetic approaches. Complexes with weakly coordinating anions [(er-NHC)AuX] (X- = BF4-, NTf2-, OTf-) were generated in solution According to their 13C NMR spectra, the ionic character of the complexes increases in the order X- = Cl- < NTf2- < OTf- < BF4-. Addnl. factors for stabilization of the cationic complexes are expansion of the NHC ring and the attachment of bulky substituents at the N atoms. These er-NHCs are bulkier ligands and stronger electron donors than conventional NHCs as well as phosphines and sulfides and provide more stabilization of [(L)Au+] cations. A comparative study was carried out of the catalytic activities of five-, six-, and seven-membered carbene complexes [(NHC)AuX], [(Ph3P)AuX], [(Me2S)AuX], and inorganic compounds of Au in model reactions of indole and benzofuran synthesis. Increased ionic character of the complexes was correlated with increased catalytic activity in the cyclization reactions. As a result, the authors developed an unprecedentedly active monoligand cationic [(THD-Dipp)Au]BF4 (1,3-bis(2,6-diisopropylphenyl)-3,4,5,6-tetrahydrodiazepin-2-ylidene Au(I) tetrafluoroborate) catalyst bearing seven-membered-ring carbene and bulky Dipp substituents. Quant. yields of cyclized products were attained in several minutes at room temperature at 1 mol % catalyst loadings. The exptl. observations were rationalized and fully supported by DFT calculations In the part of experimental materials, we found many familiar compounds, such as Chloro{1,3-bis[2,6-bis(1-methylethyl)phenyl]-4,5-dihydroimidazol-2-ylidene}gold(I)(cas: 852445-84-2Product Details of 852445-84-2)
Chloro{1,3-bis[2,6-bis(1-methylethyl)phenyl]-4,5-dihydroimidazol-2-ylidene}gold(I)(cas: 852445-84-2) belongs to imidazoles.Imidazole rings are part of unnatural cyclic peptides and are used as ester isosteres in peptidomimetic studies.
However, the application of imidazoles is not limited to the field of peptides and peptidomimetics. Product Details of 852445-84-2
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem