3457-46-3Relevant articles and documents
Microwave-assisted solvent-free catalyzed synthesis and luminescence properties of 1,2,4,5-tetrasubstituted imidazoles bearing a 4-aminophenyl substituent
Yan, Liu-Qing,Chen, Yao,Sun, Xiao-Fu,You, Mao-Jun,Chen, Xiao-Dong,Gu, Qiang,Zhang, Yu-Min
, p. 627 - 637 (2017)
A solvent-free microwave-assisted four-component synthesis of 1,2,4,5-tetrasubstituted imidazoles bearing a 4-aminophenyl substituent was studied by condensation of p-phenylenediamine, aryl diketone, benzaldehyde derivatives and ammonium acetate in the presence of solid support silica gel and catalyst Keggin-H3[PW12O40]. The effects of four components molar ratio along with catalyst loading, irradiation time on the yields were investigated. Also, the structures of synthesized compounds were characterized by FT-IR, HRMS, 1H NMR and 13C NMR spectroscopy. Furthermore, their ultraviolet-visible maximum absorption, liquid fluorescence emission maximum and quantum yields were, respectively, measured in 0.05 M H2SO4 aqueous solution and in dichloromethane. Simultaneously, solid fluorescence spectra were determined in the powder state. The relationships between the optical behavior and the polarity of the solvents for some compounds were assessed. The results showed that the fluorescence quantum efficiency was increased by introducing amino phenyl in comparison with benzyl on 1-position of trisubstitued imidazoles. The compounds synthesized were sensitive to the polarity of the solvents.
OXIDATIVE TRAPPING OF TRANSIENT THIAZOLIUM-ALDEHYDE ADDUCTS BY INTRAMOLECULAR FLAVIN. FLAVIN-THIAMINE BISCOENZYME MODEL
Shinkai, Seiji,Yamashita, Takaharu,Manabe, Osamu
, p. 961 - 964 (1981)
A biscoenzime which has within a molecular structure both flavin and thiazolium ion was synthesized.In the presence of the biscoenzyme and hexadecyltrimethylammonium bromide (CTAB) micelle, aldehydes were efficiently converted to carboxylic acids and the acyloin condensation products were scarcely detected. Thus, the biscoenzyme serves as an interesting model system for pyruvate dehydrogenase.
FACILE OXIDATION OF ALDEHYDES AND α-KETO ACIDS AS CATALYZED BY FLAVIN AND THIAZOLIUM ION
Shinkai, Seiji,Yamashita, Takaharu,Kusano, Yumiko,Manabe, Osamu
, p. 2543 - 2546 (1980)
Oxidation of aldehydes and α-keto acids to carboxylic acids occurs readily in the presence of a flavin, thiazolium ion, and cationic micelles, the reaction involving trapping by the flavin of the intermediate formed from the substrate-thiazolium adducts through deprotonation or decarboxylation.
1-butyl-3-methylimidazol-2-ylidene as an efficient catalyst for cross-coupling between aromatic aldehydes and N-aroylbenzotriazoles
Phungpis, Baramee,Hahnvajanawong, Viwat
, p. 651 - 657 (2021/02/27)
Cross-coupling of aromatic aldehydes with N-aroylbenzotriazoles in [Bmim]Br in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) provided an efficient procedure for the synthesis of 1,2-diarylethane-1,2-diones.
Catalyst-Free and Transition-Metal-Free Approach to 1,2-Diketones via Aerobic Alkyne Oxidation
Shen, Duyi,Wang, Hongyan,Zheng, Yanan,Zhu, Xinjing,Gong, Peiwei,Wang, Bin,You, Jinmao,Zhao, Yulei,Chao, Mianran
, p. 5354 - 5361 (2021/05/05)
A catalyst-free and transition-metal-free method for the synthesis of 1,2-diketones from aerobic alkyne oxidation was reported. The oxidation of various internal alkynes, especially more challenging aryl-alkyl acetylenes, proceeded smoothly with inexpensive, easily handled, and commercially available potassium persulfate and an ambient air balloon, achieving the corresponding 1,2-diketones with up to 85% yields. Meanwhile, mechanistic studies indicated a radical process, and the two oxygen atoms in the 1,2-diketons were most likely from persulfate salts and molecular oxygen, respectively, rather than water.