63384-03-2Relevant academic research and scientific papers
N-Demethylation of N,N-Dimethylanilines by the benzotriazole N-Oxyl radical: Evidence for a two-step electron transfer-proton transfer mechanism
Baciocchi, Enrico,Bietti, Massimo,Lanzalunga, Osvaldo,Lapi, Andrea,Raponi, Daniele
supporting information; experimental part, p. 1378 - 1385 (2010/06/11)
"Chemical Equation Presented" The reaction of the benzotriazole N-oxyl radical (BTNO) with a series of 4-X-N,N-dimethylanilines (X = CN, CF 3, CO2CH2CH3, CH3, OC6H5, OCH3) has been investigated in CH 3CN. Product analysis shows that the radical, 4-X-C6H 4N(CH3)CH2·, is first formed, which can lead to the N-demethylated product or the product of coupling with BTNO. Reaction rates were found to increase significantly by increasing the electron-donating power of the aryl substituents (p+ = -3.8). With electron-donating substituents (X = CH3, OC6H5, OCH3), no intermolecular deuterium kinetic isotope effect (DKIE) and a substantial intramolecular DKIE are observed. With electron-withdrawing substituents (X = CN, CF3, CO2CH2CH 3), substantial values of both intermolecular and intramolecular DKIEs are observed. These results can be interpreted on the basis of an electron-transfer mechanism from the N,N-dimethylanilines to the BTNO radical followed by deprotonation of the anilinium radical cation (ET-PT mechanism). By applying the Marcus equation to the kinetic data for X = CH3, OC 6H5, OCH3 (rate-determining ET), a reorganization energy for the ET reaction was determined (λ BTNO/DMA= 32.1 kcal mol- 1). From the self-exchange reorganization energy for the BTNO/BTNO- couple, a self-exchange reorganization energy value of 31.9 kcal mol-1 was calculated for the DMA·+/DMA couple.
Synthesis and oxidative ring contraction of 1,5,3,7-dichalcogenadiazocanes. Novel formation of 1,2,4-diselenazolidines, 1,2,4-ditellurazolidines, and 1,2,3,4,5,7-pentathiazocanes
Takikawa, Yuji,Koyama, Yutaka,Yoshida, Takamasa,Makino, Kenshiro,Shibuya, Hiroki,Sato, Kazuto,Otsuka, Tatsuya,Shibata, Yuko,Onuma, Yuki,Aoyagi, Shigenobu,Shimada, Kazuaki,Kabuto, Chizuko
, p. 1913 - 1925 (2007/10/03)
1,5,3,7-Dithiadiazocanes, 1,5,3,7-diselenadiazocanes, and 1,5,3,7-ditelluradiazocanes were prepared from a primary amine, formalin, and H2S, NaSeH, or NaTeH, respectively. Oxidation of 1,5,3,7- diselenadiazocanes and 1,5,3,7-ditelluradiazocanes using NBS efficiently afforded 1,2,4-diselenazolidines or 1,2,4-ditellurazolidines, respectively. In contrast, treatment of 1,5,3,7-dithiadiazocanes with bromine-elemental sulfur or disulfur dichloride (S2Cl2) afforded 1,2,3,4,5,7- pentathiazocanes. An unusual oxidative conversion of 1,5,3,7- dichalcogenadiazocanes into these products was assumed to proceed through in situ formation of 1,5,3,7-dichalcogenadiazabicyclo[3.3.0]octane-type dications.
