227008-56-2Relevant academic research and scientific papers
Nitrosobenzene-Enabled Chiral Phosphoric Acid Catalyzed Enantioselective Construction of Atropisomeric N-Arylbenzimidazoles
An, Qian-Jin,Xia, Wang,Ding, Wei-Yi,Liu, Huan-Huan,Xiang, Shao-Hua,Wang, Yong-Bin,Zhong, Guofu,Tan, Bin
supporting information, p. 24888 - 24893 (2021/10/20)
Described herein is an imidazole ring formation strategy for the synthesis of axially chiral N-arylbenzimidazoles by means of chiral phosphoric acid catalysis. Two sets of conditions were developed to transform two classes of 2-naphthylamine derivatives into structurally diverse N-arylbenzimidazole atropisomers with excellent chemo- and regioselectivity as well as high levels of enantiocontrol. It is worth reflecting on the unique roles played by the nitroso group in this domino reaction. It functions as a linchpin by first offering an electrophilic site (N) for the initial C?N bond formation while the resulting amine performs the nucleophilic addition to form the second C?N bond. Additionally, it could facilitate the final oxidative aromatization as an oxidant. The atropisomeric products could be conveniently elaborated to a series of axially chiral derivatives, enabling the exploitation of N-arylbenzimidazoles for their potential utilities in asymmetric catalysis.
Kinetics and mechanism of nitrosation of toluene, o-xylene, and m-xylene in trifluoroacetic acid, or in acetic-sulfuric acid mixtures, under nitric oxide
Atherton, John H.,Moodie, Roy B.,Noble, Darren R.
, p. 699 - 705 (2007/10/03)
The title reactions give good yields with m-xylene, and modest yields with toluene and o-xylene which are successfully directly nitrosated for the first time. The advantages of purging with nitric oxide are demonstrated and discussed. The kinetics have been successfully interpreted in terms of a mechanism in which both the aromatic substrate and the nitrosoaromatics form, reversibly, complexes with nitrosonium ion. The nitrosoaromatics are unstable under the acid conditions and the method is successful only because of the protective complexation with the nitrosonium ion.
