Laser Flash Photolysis Studies on the First Superoxide Thermal Source. First Direct Measurements of the Rates of Solvent-Assisted 1,2-Hydrogen Atom Shifts and a Proposed New Mechanism for This Unusual Rearrangement<sup>1</sup>
作者:Klara G. Konya、Thomas Paul、Shuqiong Lin、Janusz Lusztyk、K. U. Ingold
DOI:10.1021/ja993570b
日期:2000.8.1
A water-assisted 1,2-H shift converting benzyloxyl into the benzyl ketyl radical is an important step in the above reaction cascade. The kinetics of the 1,2-H shift assisted by H2O, D2O, and a number of nucleophilic alcohols have been measured for the first time. These data have led to a proposed new mechanism involving the initial formation of a ketyl radical anion and an oxonium cation w...
双(4-羧基苄基)次亚硝酸盐 (SOTS-1) 在生理条件下在充气水中的热分解先前已被证明以 40 mol% 的产率产生超氧自由基阴离子(Ingold, KU; et al. J. Am . Chem. Soc. 1997, 119, 12364)。通过激光闪光光解确定了从最初形成的水溶性苄氧基自由基到超氧化物的级联事件中涉及的基本反应的绝对动力学。根据这些动力学得出的结论是,SOTS-1 将适用于在大多数生物系统中研究超氧化物诱导的氧化应激。将苄氧基转化为苄基羰基自由基的水辅助 1,2-H 转变是上述反应级联中的重要步骤。由 H2O、D2O、并且首次测量了许多亲核醇。这些数据导致提出了一种新的机制,包括最初形成羰基自由基阴离子和氧鎓阳离子...