The author of 《Ruthenium(II)-Catalyzed Enantioselective γ-Lactams Formation by Intramolecular C-H Amidation of 1,4,2-Dioxazol-5-ones》 were Xing, Qi; Chan, Chun-Ming; Yeung, Yiu-Wai; Yu, Wing-Yiu. And the article was published in Journal of the American Chemical Society in 2019. Formula: C7H6N4O The author mentioned the following in the article:
We report the Ru-catalyzed enantioselective annulation of 1,4,2-dioxazol-5-ones to furnish γ-lactams in up to 97% yield and 98% ee via intramol. carbonylnitrene C-H insertion. By employing chiral diphenylethylene diamine (dpen) as ligands bearing electron-withdrawing arylsulfonyl substituents, the reactions occur with remarkable chemo- and enantioselectivities; the competing Curtius-type rearrangement was largely suppressed. Enantioselective nitrene insertion to allylic/propargylic C-H bonds was also achieved with remarkable tolerance to the C=C and CC bonds. The experimental process involved the reaction of Di(1H-imidazol-1-yl)methanone(cas: 530-62-1Formula: C7H6N4O)
Di(1H-imidazol-1-yl)methanone(cas: 530-62-1) is a peptide coupling reagent,it is used in the synthesis of peptides. Reacts readily with carboxylic acids to form acyl imidazoles; subsequent reaction with amines to form amides goes smoothly.Formula: C7H6N4O
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem