Ketene Reactions with the Aminoxyl Radical TEMPO: Preparative, Kinetic, and Theoretical Studies
作者:Annette D. Allen、Bernice Cheng、Michael H. Fenwick、Babak Givehchi、Huda Henry-Riyad、Valerij A. Nikolaev、Elena Aleksadrovna Shikhova、Daryoush Tahmassebi、Thomas T. Tidwell、Silas Wang
DOI:10.1021/jo0011336
日期:2001.4.1
reactive ketenes were generated as rather long-lived species by photochemical Wolff rearrangement in isooctane solution, characterized by IR and UV, and used for kinetic studies. The rate constants of TEMPO addition to eight different ketenes have been measured and give a qualitative correlation of log k(2)(TEMPO) = 1.10 log k(H(2)O) -3.79 with the rate constants for hydration of the same ketenes. Calculations
四甲基哌啶基氧基(TEMPO,TO *)与通过Wolff重排或酰基氯的脱氯化氢反应生成的烯酮RR(1)C = C = O反应,得到的产物是将一个TEMPO自由基加到羰基碳上,再将第二个TEMPO自由基加成激进。苯基乙烯基乙烯酮4b和4f,苯基炔基乙烯酮4c和二烯基乙烯酮AcOCMe = CHCH = CHCMe = C = O的反应发生烯丙基或炔丙基重排。通过在异辛烷溶液中进行光化学Wolff重排,甚至以相当长的寿命生成了相当活泼的烯酮,其特征在于IR和UV,并用于动力学研究。已测量了TEMPO除八种不同烯酮外的速率常数,并给出了log k(2)(TEMPO)= 1.10 log k(H(2)O)-3.79与相同烯酮水合的速率常数的定性相关性。