Chemistry of o-Di-t-butylbenzene
Chemistry of o-Di-t-butylbenzene
复制标题
邻二叔丁基苯的化学性质
DOI：
10.1021/ja01077a047
复制
发表时间：
1964
影响因子：
15
通讯作者：
M. O. Abdel
中科院分区：
文献类型：
--
作者：
A. W. Burgstahler;Ping;M. O. Abdel
本文研究了高位阻烃-二正丁基苯（Ⅰ）的各种化学和光化学反应。根据所用试剂，I的硝化得到1，2-二-正丁基-4-硝基苯（Vila）或1，2-二-正丁基-4，5-二硝基苯（Vila）。通过氟硼酸重氮盐的还原、重氮化和乙酰化，将Vila转化为3，4-二-Z-丁基苯酚乙酸酯（VUd）。相应的苯酚Vile没有显示出任何存在于互变异构二烯酮结构Xa中的趋势，其通过在o-二-Z-丁基体系中减轻应变而稳定化可能是预期的。Vile的溴化得到2，4-二溴-5-正丁基苯酚（XII）。氯化铝催化的I的乙酰化产生2，4-、3，5-和3，4-二-Z-丁基苯乙酮，加上E-Z-丁基苯乙酮，以及少量的间-和%二-Z-丁基苯和1，3，5-三-Z-丁基苯。除了3，4-二-Z-丁基苯乙酮之外，这些相同的产物也在间-和ε-二-Z-丁基苯的类似乙酰化中形成。在异丙醇存在下，I在液氨中被锂控制还原，主要得到2，3-二正丁基-1，4-环己二烯（XIX），后者被乙基氨基锂异构化为1，6-二正丁基-1，3-环己二烯（XXII）。在全石英装置中用汞弧灯照射时，I缓慢异构化为间二正丁基苯和对二正丁基苯的1：4光稳定混合物，沿着形成聚合物副产物。间二正丁基苯和间二正丁基苯也达到了同样的光稳定条件，由于邻二正丁基苯（I）中存在高度的应变，这种烃和相关化合物的化学和物理性质一直是人们感兴趣的一段时间。[3]然而，直到最近才开发出合成I的成功路线。在第一个这些I的合成是通过乙炔与二-Z-丁基乙炔的二钴羰基络合物的反应实现的。4· 5在第二种方法中，采用了从1，1，4，4-四甲基四氢萘酮开始的多步序列的两种变化。6· 7在最后一步中稍作修改，后一种路线中的一种已被用于本研究。由两个邻丁基的空间排斥引起的I中的应变能首先由以下公式预测：
Various chemical and photochemical reactions of the highly hindered hydrocarbon-di-Z-butylbenzene (I) have been investigated. Depending on the reagents used, nitration of Igave either l, 2-di-Z-butyl-4-nitro-benzene (Vila) or l, 2-di-Z-butyl-4, 5-dinitrobenzene (Villa). By reduction, diazotization, and acetolysis of the diazonium fluoroborate, Vila was converted into 3, 4-di-Z-butylphenol acetate (VUd). The corresponding phenol Vile did not show any tendency to exist in the tautomeric dienone structure Xa, whose stabilization by relief of strain in the o-di-Z-butyl system might have been expected. Bromination ofVile afforded 2, 4-dibromo-5-Z-butylphenol (XII). The aluminum chloride catalyzed acetylation of I yielded 2, 4-, 3, 5-, and 3, 4-di-Z-butylacetophenone, plus£-Z-butylacetophenone, together with minor amounts of m-and% di-Z-butylbenzene and 1, 3, 5-tri-Z-butylbenzene. With the exception of 3, 4-di-Z-butylacetophenone, these same products were also formed in the similar acetylation of m-and£-di-Z-butylbenzene. Controlled reduction of I by lithium in liquid ammonia in thepresence of isopropyl alcohol gave mainly 2, 3-di-Z-butyl-1, 4-cyclohexadiene (XIX), which was isomerized by lithium ethylamide into 1, 6-di-Z-butyl-1, 3-cyclohexadiene (XXII). On irradiation with a mer-cury arc lamp in an all-quartz apparatus I underwent slow isomerization to a 1: 4 photostationary mixture of m-and p-di-Z-butylbenzene, along with the formation of polymeric by-products. The same photostationary condition was also reached from m- and J>-di-Z-butylbenzene.Because of thehigh degree of strain present in o-di-Z-butylbenzene (I), the chemical and physical properties of this hydrocarbon and related compounds have been of interest for some time. 3 Only recently, however, have successful synthetic routes to I been developed. In the first ofthese the synthesis of I was achieved by the reaction of acetylene with a dicobalt carbonyl complex of di-Z-butylacetylene. 4· 5 In the second, two variations of a multistep sequence starting from 1, 1, 4, 4-tetramethyltetralone were employed. 6· 7 With a slight modification in the last step, one7 of the latter routes has been utilized inthe present study. The strain energy in I arising from the steric repul-sion of two oZ-butyl groups was first predicted by