Xi, 
XnRelevant articles and documents
All total 83 Articles be found
All total 83 Articles be foundNitrene-like Behaviour of Diazoazoles?
Farras, Jaume,Vilarrasa, Jaume
, p. 1127 - 1129 (1986)
Treatment of 4,5-dicyano-2-diazoimidazole, 2-diazoimidazole, amd 3-diazopyrazole with 1,1-dimethoxyethene affords azolo-as-triazines (1c), (3c), and (8c), respectively; the involvement as intermediates of either aziridines (d), arising from a 'nitrene-like reaction' of diazoazoles, or azoalkenes (b) should be questioned at present.
A sustainable approach towards the three-component synthesis of unsubstituted 1H-imidazoles in the water at ambient conditions
Kapale, Suraj S.,Chaudhari, Hemchandra K.,Mali, Suraj N.,Takale, Balaram S.,Pawar, Hitesh
, p. 712 - 716 (2020/05/22)
A green protocol for the synthesis of unsubstituted imidazoles has been demonstrated herein. The reaction is realized using commercially available lipase enzyme, porcine pancreas lipase (PPL) in water. The reaction conditions are selective and mild which helped to tolerate a wide variety of functional groups to give the desired products in good chemical yields. (Figure presented.).
Rh/TiO2-Photocatalyzed Acceptorless Dehydrogenation of N-Heterocycles upon Visible-Light Illumination
Bahnemann, Detlef W.,Balayeva, Narmina O.,Dillert, Ralf,Mamiyev, Zamin,Zheng, Nan
, p. 5542 - 5553 (2020/08/25)
TiO2 is an effective and extensively employed photocatalyst, but its practical use in visible-light-mediated organic synthesis is mainly hindered by its wide band gap energy. Herein, we have discovered that Rh-photodeposited TiO2 nanoparticles selectively dehydrogenate N-heterocyclic amines with the concomitant generation of molecular hydrogen gas in an inert atmosphere under visible light (λmax = 453 nm) illumination at room temperature. Initially, a visible-light-sensitive surface complex is formed between the N-heterocycle and TiO2. The acceptorless dehydrogenation of N-heterocycles is initiated by direct electron transfer from the HOMO energy level of the amine via the conduction band of TiO2 to the Rh nanoparticle. The reaction condition was optimized by examining different photodeposited noble metals on the surface of TiO2 and solvents, finding that Rh0 is the most efficient cocatalyst, and 2-propanol is the optimal solvent. Structurally diverse N-heterocycles such as tetrahydroquinolines, tetrahydroisoquinolines, indolines, and others bearing electron-deficient as well as electron-rich substituents underwent the dehydrogenation in good to excellent yields. The amount of released hydrogen gas evinces that only the N-heterocyclic amines are oxidized rather than the dispersant. This developed method demonstrates how UV-active TiO2 can be employed in visible-light-induced synthetic dehydrogenation of amines and simultaneous hydrogen storage applications.
