92-50-2Relevant articles and documents
Push-pull azobenzene chromophores with negative halochromism
Eom, Taejun,Khan, Anzar
, (2021)
This work describes the synthesis and properties of monoazobenzene compounds carrying multiple electron-donating and electron-withdrawing substituents. The donors are methoxy and dialkylamine groups. The acceptors are cyano and nitro groups. The position of these groups has a strong influence on the absorption spectrum. When the nitro and cyano groups are located at the ortho and para positions to the azo bond, respectively, then the absorption maximum (λmax) can be found at 484 nm. However, switching this arrangement leads to a 57 nm red-shift (λmax = 541 nm). This shift can be enhanced further (λmax = 584 and 604 nm) by moving one of the methoxy groups from the ortho to the meta position and by encompassing the nitrogen atom in a five-membered ring. Interestingly, under acidic conditions, a reversible blue-shift (negative halochromism) is observed.
Green synthesis of N-(2-hydroxyethyl)anilines by the selective alkylation reaction in H2O
Guo, Hui,Hao, Jia,Sun, Tingting,Wang, Zuoyao,Cao, Jian,Zhang, Guobao
, p. 1 - 6 (2020/07/21)
Based on our previous work, a safer and more sustainable protocol for the synthesis of N-(2-Hydroxyethyl)anilines has been developed. The synthesis included the selective alkylation reaction of aniline with 2-chloroethanol in H2O, eliminating the need for any catalysts and solvents during synthesis. Comparing with our previous work, the salient features of this methodology are eco-friendliness, economic benefit, and the ease of obtaining target compounds. The selective alkylation reaction in H2O is amenable to scale-up for the synthesis of N-(2-Hydroxyethyl)anilines.
Direct hydroxyethylation of amines by carbohydrates: Via ruthenium catalysis
Jia, Le,Makha, Mohamed,Du, Chen-Xia,Quan, Zheng-Jun,Wang, Xi-Cun,Li, Yuehui
supporting information, p. 3127 - 3132 (2019/06/18)
An efficient and halogen-free catalytic methodology for the synthesis of β-amino alcohols from aromatic amines and biomass-derived carbohydrates is demonstrated for the first time. The activation of C5/C6 sugars by a ruthenium catalyst selectively generates the C2 alkylating reagent glycolaldehyde. The transformation involves metal-catalyzed hydrogen borrowing for the reduction of the imine intermediate. A series of arylamines bearing various substituents were successfully transformed into the desired products in good to excellent yields.
