Thermolysis of Free-Radical Initiators: <i>tert</i>-Butylazocumene and Its 1,3- and 1,4-Bisazo and 1,3,5-Trisazo Analogues
作者:Paul S. Engel、Li Pan、Yunming Ying、Lawrence B. Alemany
DOI:10.1021/ja003914u
日期:2001.4.1
as a "one-radical" initiator of styrene polymerization. The ABNO-trapped cumyl radical 29 is a particularly stable trialkylhydroxylamine, whose thermolysis half-life is 2.1 h at 150 degrees C. Taking advantage of this stability, we trapped the cumyl radical centers from 7 to afford tris adduct 32a. While the behavior of the meta bisazoalkane 6 can be mostly predicted from that of 4, the para isomer
以相应的氰基苯为原料制备了四种叔丁基偶氮枯烯(4-7),并对其析氮动力学和产物进行了分析。与 TEMPO 结合使用,最简单的化合物叔丁基偶氮枯烯 (4) 有望成为苯乙烯聚合的“单自由基”引发剂。ABNO 捕获的枯基自由基 29 是一种特别稳定的三烷基羟胺,其热解半衰期在 150 摄氏度时为 2.1 小时。利用这种稳定性,我们从 7 捕获枯基自由基中心以提供三加合物 32a。虽然间位双偶氮烷 6 的行为大部分可以从 4 的行为中预测,但对位异构体 5 表现出不寻常的产物和动力学,归因于通过含偶氮自由基 34 形成醌二甲烷 33。事实上,