Evidence for a free radical mechanism in the decomposition of bis(but-2-enyl) tellurium
作者:John Stevenson、William Bell、Joseph Ferry、David J. Cole-Hamilton、Janet E. Hails
DOI:10.1016/0022-328x(93)80117-t
日期:1993.5
coupling of the allyl radicals formed, particularly as no compounds containing CH2CHCHMeTe are recovered after partial pyrolysis. The products can be fitted to a purely statistical model in which the reactivity ratio of the primary to secondary allyl is ca. 0.63:0.37. The statistical fit is taken to indicate that mechanisms other than that involving homolytic fission and free radical coupling play a negligible
Na 2 Te的碱性水溶液与MeCH = CHCH 2 Br或CH 2 = MCHMeCl反应,得到ZZ-,ZE-和EE-(MeCH = CHCH 2)2 Te。这是根据在碱性反应条件下涉及Na 2 Te攻击由烯丙基卤形成的2-丁烯基阳离子的机理来解释的。给出E-构型的反应速率为约2。形成Z的3倍。的分解(MeCHCHCH 2)2液相或气相中的Te会产生所有可能的产物,这些产物是由烯丙基的二聚化产生的。这是根据TeC键的均质裂变,然后偶联形成的烯丙基进行解释的,特别是因为部分热解后未回收到含CH 2 = CHCHMeTe的化合物。可以将产物拟合为纯统计模型,其中伯烯丙基与仲烯丙基的反应比为ca。0.63:0.37。统计拟合表明,除涉及均质裂变和自由基偶联的机制外,其他机制所起的作用可忽略不计。