通过电子能量损失谱研究了2,2-二甲基异茚(1)的激发电子态。其垂直气相三重态(1 3 B 2)和单重态(1 1 B 2)的激发能分别为1.61和3.19 eV。因此,与用作参考化合物的(全-E)-辛酸酯的相应状态相比,激发态分别降低了0.49eV和1.21eV。这些偏移通过ZINDO计算得到了部分重现。光谱没有证据表明低于1 1 B 2的2 1 A g状态状态,但这种缺乏观察并不能排除其存在。最低的三重态T 1(1)的特征还在于快速光解。观察到T 1(1)为瞬态中间体,λ≤350 nm,在脱气己烷中的寿命为8m̈s。通过能量转移实验,T 1(1)的绝热激发能被包围在1.1±0.1 eV的范围内。讨论了最低激发单重态和三重态1的能量与其自由基阳离子的最低激发二重态(基本上是非库普曼态)之间的关系。
The stereochemistry of forward and reverse reactions in the addition of hydridocobaloxime to (E)-1-phenylpropene
作者:Sylvie Derenne、Alain Gaudemer、Michael D. Johnson
DOI:10.1016/0022-328x(87)85010-6
日期:1987.3
deuteriocobaloxime to (E)-1-phenylpropene and to indene is stereoselective, the product of cis-addition predominating. When stereoselectively labelled 2-[2H1]-1-phenylpropylcobaloxime decomposes in the presence of oxygen in hydroxylic solvents, the intermediate organicradicals are intercepted by oxygen and then cobaloxime(II) to give the corresponding racemic organoperoxycobaloxime in good yield. However
氘代钴钴肟向(E)-1-苯基丙烯和茚的加成是立体选择性的,顺式加成的产物占主导。当立体选择标记的2- [ 2 H 1 ] -1-苯基丙基钴肟在氧气中在羟基溶剂中分解时,中间的有机基团被氧气拦截,然后被钴肟(II)拦截,从而以高收率得到相应的外消旋有机过氧钴肟。但是,氧以固态的立体定向发生在1-苯基丙基钴肟的碳-钴键中。这些结果表明加成反应是通过氢原子从氢化钴钴肟到烯烃的均质转移而发生的。其次是立体定向在溶剂笼中通过钴肟(II)片段顺式捕获新有机自由基,但是在溶液中已经存在的通过钴肟(II)进行一些反式捕获也发生在有限的范围内。
Substituent effects on the efficiencies and regioselectivities of the di-π-methane rearrangement of vinyl-substituted bicyclic systems
作者:Helfried Hemetsberger、Matthias Nobbe
DOI:10.1016/s0040-4020(01)85094-8
日期:1988.1
- which were mono- or disubstituted at the vinyl moiety were synthesized. The substituent effects on the efficiencies and regioselectivities of the di-π-methanerearrangement were studied with the results: 1) The dihydrobenzobarrelene system rearranges less efficiently than the 7,7-benzonorbornadiene system. 2) The effect of the substituents on the efficiencies is more pronounced in the less efficient
A photobisdecarbonylation route to isoindenes: a new sythesis of 2,2-dimethyl-and 2,2-spirocyclopentyl-isoindene
作者:Ronald N. Warrener、Peter A. Harrison、Richard A. Russell
DOI:10.1039/c39820001134
日期:——
The title isoindenes have been prepared by u.v. photolysis of the appropriate 7,7-disubstitued benzonorbornene-2,3-diones, the syntheses of which are described.
通过适当的7,7-取代的苯并降冰片烯-2,3-二酮的紫外光解已制备了标题异茚,其合成方法已描述。
2,2-Dimethylisoindene and 5,5-dimethylbenzobicyclo[2.1.0]pent-2-ene
作者:William R. Dolbier、Kazumasa Matsui、Josef Michl、David V. Horak
DOI:10.1021/ja00453a076
日期:1977.5
DOLBIER W. R. JR.; MATSUI KAZUMASA; DEWEY H. J.; HORAK D. V.; MICHL J., J. AMER. CHEM. SOC., 1979, 101, NO 8, 2136-2139
作者:DOLBIER W. R. JR.、 MATSUI KAZUMASA、 DEWEY H. J.、 HORAK D. V.、 MICHL J.