激光闪光光解和动力学竞争产物研究表明,在环境温度下,在异辛烷中,以碳为中心的自由基与持久性氮氧化合物的偶联速率常数 k T 取决于偶联的空间位阻程度和共振稳定的程度。碳自由基。对于氮氧化合物结构和碳自由基结构的变化,观察到 k T 大小的空间诱导减少。因此,对于任何特定的碳基,k T 对于 Bredt 规则保护的氮氧化物、9-氮杂双环 [3.3.1] 壬烷-N-氧基 (ABNO) 和去甲托烷-N-氧基而言是最大的,而对于通常的'二叔-烷基氮氧化物 k T 沿系列递减,1,1,3,3-四甲基异碘啉-2-氧基≥2,2,5,5-四甲基哌啶-1-氧基(Tempo)>二叔丁基氮氧化物,i.
Efficient oxidation of alcohols electrochemically mediated by azabicyclo-N-oxyls
摘要:
Preparation of azabicyclo-N-oxyls and the electrochemical oxidation of alcohols using them as mediators have been exploited. This oxidation was applicable to a transformation of sterically hindered secondary alcohols into the corresponding ketones in high yields. (C) 2007 Elsevier Ltd. All rights reserved.
Calorimetric and equilibrium studies on some stable nitroxide and iminoxy radicals. Approximate oxygen-hydrogen bond dissociation energies in hydroxylamines and oximes