52287-53-3Relevant articles and documents
Design and synthesis of a novel quinoxaline diamine and its polyimides with high-Tg and red color
Liu, Tuan-Qing,Zheng, Feng,Ding, Tong-Mei,Zhang, Shu-Yu,Lu, Qinghua
, (2019)
To produce high-temperature polyimide (PI) films meeting the demand of flexible-display, heteroaromatic monomers were extensively investigated. Quinoxaline is one kind of the most important N-heterocycles, which possesses pharmacological activities and thermotolerance. In this work, newly designed diamine monomer 3/2-(4-aminophenyl)-2/3-methylquinoxalin-6-amine (QMDA) was successfully synthesized. Their corresponding quinoxaline-containing PI films were prepared by cooperating QMDA with several aromatic dianhydrides, and divided into two series according to different thermal imidization procedures. The firm scaffold of quinoxaline was proved to enhance the thermal stability of the obtained PIs. The effect of final annealing temperature on molecular packing and thermal properties of the PI films was also investigated. Under higher annealing temperature, PI films were found to pack more tightly due to the formation of more cross-linkings in polymer matrix. The restriction of chian movements brought these PIs higher Tg more than 500 °C or even prevented the occurace of glass transition.
Regioselective Opening of Nitroepoxides with Unsymmetrical Diamines
Nosood, Yazdanbakhsh L.,Ziyaei Halimehjani, Azim,González, Florenci V.
, p. 1252 - 1258 (2018/02/09)
Nitroepoxides are easily transformed into benzodiazepines, tetrahydrobenzodiazepines, imidazopyridines, and N-alkyl tetrahydroquinoxalines by treatment with 2-aminobenzylamines, 2-aminopyridines, and N-alkyl 1,2-diaminobenzenes, respectively. Regioselectivity is controlled through attack of the most nucleophilic nitrogen of the unsymmetrical diamine to the β position of the epoxide. These reactions represent an efficient way to prepare privileged bioactive structures.
Enantioselective hydrogenation of α,β-disubstituted nitroalkenes
Li, Shengkun,Huang, Kexuan,Zhang, Xumu
supporting information, p. 8878 - 8881 (2014/08/05)
The first highly chemo- and enantioselective hydrogenation of α,β-disubstituted nitroalkenes was accomplished with rhodium/JosiPhos-J2 as a catalyst, with the yield and enantioselectivity of up to 95% and 94%, respectively. The α-chiral nitroalkanes will provide an entry to valuable chiral amphetamines which are otherwise not so easily accessed. This journal is the Partner Organisations 2014.