29969-49-1Relevant articles and documents
Chemiluminescence of 1,1′-biisoquinolinium and 2,2′-biquinolinium salts. Reactions of electron-rich olefins with molecular oxygen
Mori, Yukie,Isozaki, Kumiko,Maeda, Koko
, p. 1969 - 1976 (1997)
2,2′-Dialkyl-1,1′-biisoquinolylidenes (BIQ), having been prepared by two-electron reduction of the corresponding diquaternary salts BIQ2+(X-)2, react with triplet dioxygen to produce chemiluminescence (CL). In aprotic solvents, the kinetics of the reaction are first-order with respect to the concentrations of the substrate and of oxygen. The second-order rate constants at 25°C increase in the order DMF 2, although this process is endothermic in all three solvents. In non-polar solvents such as benzene, the reaction proceeds much more slowly. From these results, a reaction mechanism is proposed as follows. An ET or partial charge-transfer gives a radical ion pair {BIQ.+ ... O2.-} or a CT complex, in which intersystem crossing takes place from the triplet to the singlet state, and then radical coupling at the 1-position followed by cyclisation yields a 1,2-dioxetane, the postulated intermediate of the CL reaction. An electron-rich olefin having a closely related structure, 1,1′-dimethyl-2,2′-bisquinolylidene (BQ), shows a similar redox behaviour to that of BIQ. Reaction of BQ with O2 produces CL, and the emitter has been identified as the singlet excited state of 1-methyl-2(1H)-quinolinone 8a. The effects of substituents in the quinoline ring on the autoxidation rate have been investigated in MeCN and DMSO. An olefin having the more negative oxidation potential shows the higher reactivity to O2, suggesting that the autoxidation of BQ should take place via a similar reaction pathway as that of BIQ.
Silver-Catalyzed Decarboxylative Radical Addition/Cyclization of Oxamic Acids with Alkenes towards Quinolin-2-ones
Jin, Chengan,He, Jing-Yao,Bai, Qi-Fan,Feng, Gaofeng
, p. 1517 - 1522 (2020/08/10)
An efficient silver-catalyzed tandem decarboxylative radical addition/cyclization of oxamic acids with alkenes has been developed. This method provides a novel and straightforward protocol toward a variety of 4-aryl-3,4-dihydroquinolin-2(1 H)-ones, 4-(α-c
Reactive 2-quinolones dearomatized by steric repulsion between 1-methyl and 8-substituted groups
Chen, Xin,Kobiro, Kazuya,Asahara, Haruyasu,Kakiuchi, Kiyomi,Sugimoto, Ryuichi,Saigo, Kazuhiko,Nishiwaki, Nagatoshi
, p. 4624 - 4630 (2013/06/26)
Usual 1-methyl-2-quinolone (MeQone) derivatives are not reactive because of aromatic property in the heterocyclic ring. On the other hand, 8-substituted MeQones have been proved to be highly reactive, which is caused by steric repulsion between the 1-meth