66394-50-1Relevant articles and documents
An enolate ion as a synthon in biocatalytic synthesis of 3,4-dihydro-2(1: H)-quinoxalinones and 3,4-dihydro-1,4-benzoxazin-2-ones: Lemon juice as an alternative to hazardous solvents and catalysts
Petronijevi?, Jelena,Bugar?i?, Zorica,Bogdanovi?, Goran A.,Stefanovi?, Srdan,Jankovi?, Nenad
, p. 707 - 715 (2017)
Innovative, efficient, clean, experimentally simple and environmentally friendly one-pot biocatalytic synthesis of two small libraries of 3,4-dihydro-2(1H)-quinoxalinones (4a-m) and 3,4-dihydro-1,4-benzoxazin-2-ones (5a, 5b, 5f and 5k-o) by heterocyclization of ethyl 2-hydroxy-4-alkyl(aryl)-4-oxo-2-butenoates (1a-o) or their corresponding salts (1a′-o′) with o-phenylenediamine (2) or o-aminophenol (3) in lemon juice as a solvent and a catalyst is presented. In all reactions where esters 1a-o are used for 24 h, very good-to-excellent yields were achieved, but the best yield was realized in the synthesis of 5a (97%) from 3 and 1a. The use of enolate salts (1a′-o′) instead of the corresponding esters 1a-o significantly reduced the reaction time (up to 6 h) and good-to-excellent yields were achieved. Groups with electron-donating or -withdrawing effects at the aromatic ring of the ester did not have significant influences on the yield of targeted products. In addition, several selected 3,4-dihydro-2(1H)-quinoxalinones and 3,4-dihydro-1,4-benzoxazin-2-ones on a gram-scale in the yields up to 92% were synthesized. The presented synthetic strategy has produced smaller amount of waste without by-products and with excellent values of green chemistry metrics (atom efficiency, reaction mass efficiency, E-factor and EcoScale).
A combination of heterogeneous catalysis and photocatalysis for the olefination of quinoxalin-2(1H)-ones with ketones in water: a green and efficient route to (Z)-enaminones
Xu, Jun,Huang, Lin,He, Lei,Ni, Zhigang,Shen, Jiabin,Li, Xiaoling,Chen, Kaixian,Li, Wanmei,Zhang, Pengfei
supporting information, p. 2123 - 2129 (2021/03/26)
Herein, a novel aqueous reaction for the olefination of quinoxalin-2(1H)-ones with ketones through a combinational strategy is described. This reaction features very mild conditions using a simple and cheap catalyst for the synthesis of (Z)-enaminones with moderate-to-good yields. Such a methodology successfully combines the heterogeneous Mannich reaction with photocatalysis, and provides a green and practical approach for the synthesis of potentially bioactive (Z)-enaminones with a 3,4-dihydroquinoxalin-2(1H)-one skeleton.
Study on the structureeproperty relationship in a series of novel BF2 chelates with multicolor fluorescence
Yao, Qi-Chao,Wu, Ding-Er,Ma, Ru-Zheng,Xia, Min
, p. 1 - 9 (2013/10/08)
A series of multicolor fluorescent N,O-bidentate BF2 complexes with variable ligand structures have been synthesized. These complexes exhibit the solvent-independent optical properties and large Stoke shifts. The electrochemical measurements demonstrate that all these chelates are better electron acceptors than the commonly used material Alq3. A qualitative structureeproperty relationship among these complexes has been established on the ground of the experimental data along with the density functional theory (DFT) calculations. The theoretically calculated results are in good agreement with those obtained by the experimental determinations.
