1629-75-0Relevant articles and documents
Mechanism of the CuII-catalyzed benzylic oxygenation of (aryl)(heteroaryl)methanes with oxygen
Sterckx, Hans,De Houwer, Johan,Mensch, Carl,Caretti, Ignacio,Tehrani, Kourosch Abbaspour,Herrebout, Wouter A.,Van Doorslaer, Sabine,Maes, Bert U. W.
, p. 346 - 357 (2016)
A mechanistic study of the copper-catalyzed oxidation of the methylene group of aryl(di)azinylmethanes was performed. Initial reaction rates were measured making use of in situ IR reaction monitoring and a kinetic analysis of the reaction was executed. The reaction proved to be first order in oxygen concentration. For substrate and acid concentration, saturation kinetics due to O2 mass transfer limitation were observed. The occurrence of mass transfer limitation was further confirmed by examining the effect of the stirring rate on the initial reaction rate. Interestingly, the effect of the concentration of the catalyst on the rate shows that higher loadings result in a maximal initial rate, followed initially by a steady decrease and subsequently a rate plateau when the concentration is increased further. Mass transfer limitation and increased concentration of dinuclear catalytically active species rationalizes this hitherto unprecedented rate behavior. Continuous-wave and pulsed electron paramagnetic resonance methods were used to characterize the catalytic species present in the solution during the reaction and confirmed the presence of both mono- and dinuclear copper species. Analysis of a diverse substrate scope points towards imine-enamine tautomerization as a crucial process in the oxidation reaction. DFT calculations of these equilibrium constants (pKeq) provided us with a qualitative tool to predict whether or not a substrate is viable for oxidation under the reaction conditions developed.
S 8-Mediated Cyclization of Bis(2-aminophenyl) Disulfide/Diselenide with Arylacetylenes/Styrenes: Access to 2-(Arylmethyl)-1,3-benzothiazoles/benzoselenazoles
Gan, Haifeng,Feng, Caojian,Zhao, Lihuan,Cao, Mengru,Wu, Hongli
supporting information, p. 70 - 75 (2021/11/17)
A novel S8-mediated approach to benzothiazoles/benzoselenazoles from bis(2-aminophenyl) disulfides/diselenides and phenylacetylenes or styrenes has been developed. 2-(Arylmethyl)-1,3-benzoselenazoles were comprehensively synthesized for the first time. The reactions proceeded in moderate to excellent yields, and with a gramscale application.
One-pot synthesis of 2-acylbenzothiazoles from 2-aminobenzenethiols and arylacetonitriles via cyclization and sequential oxidation
Zhang, Shanshan,Wang, Shiwei,Leng, Yuting,Wu, Yangjie
, (2021/08/13)
An efficient one-pot method to access 2-acylbenzothiazoles via AlCl3-mediated cyclization reaction and I2-promoted sequential oxidation reaction of 2-aminobenzenethiols with arylacetonitriles was developed. This reaction proceeds smoothly with a wide range of arylacetonitriles containing different functional groups to give the corresponding products in moderate to good yields under mild conditions. Moreover, this reaction was conveniently conducted on a gram scale, and the yield is still up to 68%.
C2-arylacylation of 2H-benzothiazoles with methyl arenes via Selectfluor oxidation
Chen, Bo,Kong, Yao-Lei,Liu, Jin-Chuan,Lu, Qi,Sun, Xiao-Tong,Weng, Jian-Quan
, (2021/06/03)
An efficient Selectfluor-oxidative protocol was developed for the direct C2-arylacylation of 2H-benzothiazoles via the radical reaction of 2H-benzothiazoles with methyl arenes. Selectfluor can effectively promote the oxidative cross-coupling without an ex
